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000
FXUS66 KOTX 251129
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
427 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Today through Sunday...General trof pattern continues to influence
the sensible weather over Eastern Washington and Northern Idaho
keeping it unsettled at times along with temperatures on the cool
side of what would be considered normal this time of year. Last
few HRRR model runs hit at surface based convection over the
northern mountains after 11AM PDT today and upon further inspection
GFS runs for this interval show the cold pool aloft at 500mb
helping to keep the instability overhead extends west to overhang
parts of the cascades...thus the minor mention of afternoon and
early evening thunderstorms has been stretched westward to cover
parts of the East Slopes of the Northern cascades roughly north of
Leavenworth. Models also hint at a mesoscale shortwave or two
producing enough forcing to allow for some minor mention of
showers overnight...one near the cascades and the other passing
over the Blue Mountains up into North Idaho Panhandle. Sunday the
trof overhead is very very cluttered with synoptic and mesoscale
shortwave propagation through it which allows for the mention of
showers to persist. Forecast temps show a very slight cooling
trend as the flow turns a bit more southerly, which is a warm
trajectory most of the time, for Sunday. Additionally since the
jet stream is south of the forecast area through this time
interval resulting in a lowered tropopause (down to near 400mb)
some of these showers could produce the typical early spring
precipitation type (graupel or soft hail) for a spell along with
mixing moderate wind gusts down to the surface which is something
to keep in mind over the weekend. /Pelatti
Sunday Night through Wednesday: The cool upper level trough that
has been anchored over the Pacific Northwest since Wednesday is
expected to pivot into western Montana Sunday night into Monday
bringing scattered showers to the eastern third of Washington and
northern Idaho. Despite the displacement of this upper low, our
weather pattern isn`t expected to change much. There is good
agreement between the medium range models that the Polar Jet will
dive into southern Oregon and carve another upper level trough
over the Pacific Northwest. The best jet dynamics (Q-Vector
Divergence) Monday night into Tuesday should be over southern
Oregon into the Great Basin, but there will be enough moisture and
deep layer instability with the weakening frontal occlusion to
maintain a good chance of showers Tuesday and Tuesday night.
Depending on the timing of this system, we may need to add a
mention of thunderstorms on Tuesday. The 00z GFS, Canadian and
ECMWF are in pretty good agreement with a weak, negatively tilted
trough over central and western Washington. The GFS and ECMWF
are producing precipitation that looks convectively driven over
the north Cascades. The potential for thunderstorms over the burn
scars around Wenatchee, Ellensburg, and Chelan will be a concern
through the summer and we will continue to monitor patterns like
this one closely for mudslides and debris flows.
The axis of a west to east oriented upper trough is expected to
linger over the Pacific Northwest Wednesday and through the end of
the week. It does look like Tuesday`s frontal occlusion will bring
the most widespread shower activity to the region this week, but
afternoon and early evening showers will be in the forecast for
much of the week. /GKoch
Wednesday Night through Friday Night: Through this time frame we
continue to see an unsettled pattern that will continue to feature
the chance for precipitation across most of the Inland NW
especially for the higher terrains of the ID Panhandle along with
Cascade Crests earlier in the period. Models are in pretty good
agreement through Friday Afternoon by keeping a large scale
negatively tilted trough pattern in place allowing for moisture to
flow in behind the low center that pushes to our SE throughout the
night on Wednesday. With the increased moisture, there will be
thick cloud cover keeping temps in the lower 60s and 70s for
most correlating to below normal temps for this time of year. Low
temps will follow the same pattern of a couple degrees below
normal due to the lack of daytime heating. Towards the end of the
period models are indicating a ridge builds behind the exiting
trough which should help to diminish the precipitation
threat...lower the cloud coverage and ultimately push temperatures
closer to seasonal averages as we approach next weekend. Overall
not many changes were made to the forecast..just tinkered with the
POPs slightly to reflect most recent model data and trended the
temps in the same manner. /Fliehman
&&
.AVIATION...
12Z TAFS: General trof over Eastern Washington and Northern Idaho
continues through this interval. Some late night and early morning
valley fog primarily in northern valleys with some showers at
times...primarily in the afternoon and early evening. VFR ceilings
and visibilities are expected to pravail through the 24 hour
interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 50 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 50 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 50 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 50 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 63 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 61 44 63 46 62 47 / 40 20 30 60 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
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000
FXUS66 KSEW 251026
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PDT SAT MAY 25 2013
.SYNOPSIS...A WEAKENING LOW PRESSURE SYSTEM WILL REMAIN OVER THE
REGION THROUGH THIS WEEKEND BUT THERE WILL BE A TREND TOWARD LESS
SHOWERS...MORE SUNSHINE...AND WARMER AFTERNOON TEMPERATURES. A WEAK
SYSTEM MAY LIFT NORTH THROUGH WESTERN WASHINGTON ON MEMORIAL DAY.
RAIN WILL INCREASE FROM SOUTH TO NORTH DURING THE AFTERNOON AND
EVENING. EXPECT SCATTERED SHOWERS AND COOLER WEATHER THROUGH AT
LEAST MIDWEEK.
&&
.SHORT TERM...WESTERN WASHINGTON IS STILL UNDER THE INFLUENCE OF THE
SPIRALING UPPER LEVEL LOW THAT HAS BEEN OVER THE REGION FOR THE
PAST SEVERAL DAYS. THE MAIN LOW CENTER IS OVER SOUTHERN
ALBERTA...BUT IT LOOKS LIKE THERE IS A SECOND /WEAKER/ CENTER OVER
WA. AS A RESULT...WE WILL CONTINUE TO SEE ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION TODAY. POPS ARE HIGHEST OVER THE SOUTHERN
PORTION OF THE CWA /WHERE THE FLOW IS WESTERLY/. TEMPS ARE RATHER
TRICKY UNDER THIS PATTERN. A FEW SUNBREAKS AND WE WILL SEE LOWER 60S
BUT AREAS STUCK UNDER THE CLOUDS WILL REMAIN IN THE 50S. THIS
SECONDARY VORT LOBE OVER WA WILL MAINTAIN A CHANCE OF SHOWERS ACROSS
THE REGION TONIGHT.
SHOWERS WILL DECREASE ON SUNDAY AS THE BROAD UPPER LEVEL LOW FINALLY
EXITS TO THE EAST. SHOWERS WILL MAINLY AFFECT THE MOUNTAINS AND
SOUTH PART DURING THE MORNING AND EARLY AFTERNOON. BUT AS WE HEAD
INTO THE LATE AFTERNOON AND EVENING HOURS WE SHOULD SEE SHOWERS
DIMINISHING ACROSS THE BOARD.
MODELS ARE STILL WAFFLING WITH THE STRENGTH AND TIMING OF THE NEXT
SYSTEM SLATED FOR MEMORIAL DAY. IT NOW LOOKS LIKE THIS SYSTEM
WILL LIFT NORTH THROUGH OREGON DURING THE MORNING...WITH RAIN
REACHING THE COAST AND SOUTH PART OF THE CWA DURING THE AFTERNOON.
THE UPPER LEVEL TROUGH WILL THEN CROSS THROUGH WESTERN WA DURING THE
EVENING FOR AN INCREASING CHANCE OF SHOWERS. THIS SYSTEM DOES WEAKEN
AS IT MOVES INLAND SO WILL STILL STICK WITH LOWER POPS. MODEL QPF IS
UP TO ONE QUARTER OF AN INCH FOR THE COAST AND SOUTH PART...WITH
ONLY A FEW HUNDREDTHS SEATTLE NORTHWARD. 33
.LONG TERM...MODELS CONTINUE THE TREND OF COOL AND SHOWERY WEATHER
ACROSS WESTERN WA THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. WED MAY
BE THE WETTEST DAY AS A NEGATIVE TILT TROUGH AXIS LIFTS NORTH
THROUGH THE STATE. BUT THE MODELS ARE ADVERTISING A BREAK IN THE
ACTION STARTING THURSDAY AS A BROAD UPPER LEVEL RIDGE OVER THE NE
PAC NUDGES INLAND. THIS PATTERN MAY CONTINUE ON FRIDAY AND INTO THE
WEEKEND. SO IF THIS HOLDS THEN LOOK FOR DRIER WEATHER THROUGHOUT
THIS PERIOD. 33
&&
.AVIATION...WEAK UPPER LEVEL TROUGH REMAINING OVER WESTERN
WASHINGTON TODAY WITH LIGHT SOUTHWESTERLY FLOW ALOFT. LIGHT LOW
LEVEL FLOW AS WELL. AIR MASS MOIST AND SLIGHTLY UNSTABLE.
IN GENERAL...CEILINGS IN THE 4000 TO 6000 FOOT RANGE WITH CEILINGS
AS LOW AS 1500 FEET NEAR SHOWERS. SOME BRIEF SCATTERING OUT OF THE
CLOUD DECK POSSIBLE THROUGHOUT THE DAY.
KSEA...S WIND 4 TO 8 KNOTS TODAY. VFR CIGS EXPECTED...DROPPING TO
MVFR BRIEFLY DURING SHOWERS. FELTON
&&
.MARINE...LIGHT GRADIENTS TODAY AS A WEAK SURFACE LOW OVER THE
OFFSHORE WATERS MOVES SOUTHEAST AND DISSIPATES. LIGHT ONSHORE FLOW
DEVELOPING ON SUNDAY. THE NEXT ORGANIZED FRONT REACHES THE WATERS ON
MONDAY WITH SMALL CRAFT WINDS POSSIBLE OVER THE COASTAL WATERS.
ONSHORE FLOW PATTERN WILL RESUME FOR TUESDAY AND WEDNESDAY. FELTON
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...NONE.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
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000
FXUS66 KPQR 251023
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
322 AM PDT SAT MAY 25 2013
.SYNOPSIS...IT APPEARS COOL AND WET CONDITIONS WILL LINGER ACROSS
SOUTHWEST WASHINGTON AND NORTHWEST OREGON FOR MUCH OF THE MEMORIAL
DAY WEEKEND. BROAD UPPER LEVEL LOW PRESSURE WILL LINGER ACROSS
SOUTHWESTERN CANADA AND THE NORTHWESTERN UNITED STATES FOR THE NEXT
SEVERAL DAYS...WITH A SERIES OF DISTURBANCES BRINGING OCCASIONAL RAIN
TO THE FORECAST AREA. THE NEXT WEAK LOW PRESSURE SYSTEM WILL BRING AN
INCREASING CHANCE FOR RAIN AS TODAY PROGRESSES...WITH STEADY RAIN
LIKELY THROUGHOUT THE DISTRICT TONIGHT AND EARLY SUNDAY BEFORE
TAPERING TO SHOWERS LATER SUNDAY AFTERNOON. A STRONGER SYSTEM SHOULD
SPREAD MORE RAIN ACROSS THE DISTRICT MONDAY...POSSIBLY ALONG WITH A
BRIEF PERIOD OF BREEZY CONDITIONS ALONG THE COAST. BRISK WESTERLY
FLOW WILL KEEP THINGS UNSETTLED WITH RAIN AT TIMES INTO MIDWEEK.
&&
.SHORT TERM...MOST OF THE FORECAST AREA IS STARTING OUT THE DAY
CLOUDY BUT DRY FOR A CHANGE...ASIDE FROM A FEW SHOWERS MAINLY ACROSS
PORTIONS OF CLARK COUNTY AND THE S WA COAST. THERE ARE SOME BREAKS IN
THE CLOUDS ACROSS THE WILLAMETTE VALLEY SALEM SOUTHWARD...WHERE THERE
MAY BE SOME SUNSHINE THIS MORNING. HOWEVER WEAK ISENTROPIC LIFT OUT
AHEAD OF AN APPROACHING WEAK LOW PRESSURE SYSTEM WILL CAUSE CLOUDS TO
INCREASE THROUGHOUT THE DAY. RAIN CHANCES WILL INCREASE ALONG THE
COAST BY AFTERNOON AND INLAND BY THIS EVENING. TODAY MAY BE THE
WARMEST OF THE NEXT FEW...ESPECIALLY NEAR EUGENE WHERE SOME SUNSHINE
MAY WARM TEMPS INTO THE MID TO UPPER 60S.
THE WEAK LOW WILL MOVE ONSHORE OVERNIGHT TONIGHT. WEAK FLOW PATTERN
WILL RESULT IN MINIMAL OROGRAPHICS...AND LITTLE TO NO RAINSHADOWING
FOR THE WILLAMETTE VALLEY. SO AGAIN THERE COULD BE A GOOD BIT OF
STEADY RAIN IN THE LOWLANDS TONIGHT INTO SUNDAY MORNING. NOT
EXPECTING THE SAME KIND OF TOTALS WE EXPERIENCED AROUND PORTLAND THE
LAST FEW DAYS...BUT THIS WILL PROBABLY BE A HEAVIER EVENT FOR SALEM
AND EUGENE WHO RECEIVED LESS PRECIP FROM THE LAST COUPLE OF SYSTEMS.
THERE IS A BIT OF QUESTION AS TO WHETHER RAIN WILL BE STEADY OR MORE
SHOWERY SUNDAY AFTERNOON AS THE ASSOCIATED UPPER LOW MOVES ONSHORE.
NAM BUFR SOUNDINGS SHOW A VERY MOIST AIR MASS BUT LITTLE IN THE WAY
OF INSTABILITY. REGARDLESS WE ARE STARTING TO SUSPECT TEMPS MAY AGAIN
HAVE A HARD TIME GETTING OUT OF THE 50S SUNDAY IN A VERY CLOUDY AND
WET DAY.
PRECIPITATION WILL TAPER OFF AS THIS SYSTEM MOVES EAST SUN EVENING...
JUST IN TIME FOR A MORE ORGANIZED PACIFIC FRONTAL SYSTEM TO MOVE
ONSHORE LATER SUNDAY NIGHT OR MONDAY/MEMORIAL DAY MORNING. DEPENDING
ON THE TRACK OF THIS SYSTEM IT MAY HAVE A BRIEF PUNCH OF MODEST
COASTAL WIND WITH IT...BUT THIS APPEARS MORE LIKELY FOR SOUTHERN
OREGON OR NORTHERN CALIFORNIA WHERE THE BEST JET DYNAMICS WILL BE. AS
A RESULT THIS SYSTEM MAY TRY TO SPLIT SOMEWHAT AS IT MOVES ONSHORE...
BUT STILL SHOULD HOLD TOGETHER ENOUGH FOR A DECENT RAIN MEMORIAL DAY.
THE GOOD NEWS IS THAT SNOW LEVELS WILL PROBABLY REMAIN ABOVE THE
PASSES THROUGH THE HOLIDAY WEEKEND. WEAGLE
.LONG TERM...MADE VERY FEW CHANGES FOR THE EXTENDED PERIOD. GENERAL
MODEL TREND REMAINS WET MIDWEEK FOLLOWED BY MORE SEASONABLE WEATHER
LATER IN THE WEEK. PREVIOUS DISCUSSION FOLLOWS...MODELS START OUT IN
GOOD AGREEMENT DURING THE EXTENDED PERIOD MON NIGHT AND TUE...WITH A
TROUGH PUSHING INLAND OVER THE WEST COAST. MOST OF THE ENERGY APPEARS
HEADED S OF THE FORECAST AREA TOWARDS CA. AS THE NORTHERN STREAM
APPEARS TO REMAIN AN OPEN WAVE...WILL BOOST POPS INTO LIKELY
CATEGORY. MODELS DIVERGE SOME LATER IN THE WEEK...BUT KEEP A COMMON
THEME OF SHORTWAVES PUSHING IN IN A WESTERLY FLOW ALOFT. WILL KEEP
POPS RELATIVELY HIGH FOR A SYSTEM ON WED...BUT THEN WILL DROP POPS
OFF LATER IN THE WEEK AS UPPER HEIGHTS RISE.
&&
.AVIATION...PREDOMINANT MVFR OR BETTER ACROSS THE AREA ALTHOUGH
WEAK LOW-LEVEL CONVECTIVE ELEMENTS HAVE BROUGHT BRIEF MVFR CIGS
UNDER SHOWERS. WILL SEE THIS PATTERN CONTINUE THROUGH EARLY
DAYLIGHT HOURS BUT WITH SHOWERS PRIMARILY CONFINED TO THE NORTHERN
COASTAL AREAS. WILL THEREAFTER SEE MID-LEVEL RAIN DEVELOP TOWARD
AFTERNOON WITH CIGS AGAIN CLOSING UP BUT LIKELY STAYING MVFR OR
BETTER. SHOULD SEE RAIN CONTINUE BEFORE EASING LATE OVERNIGHT AT
THE COAST AND EARLY SUNDAY MORNING INLAND.
KPDX AND APPROACHES...OCCASIONAL WEAK SHOWERS CONTINUE TO FORM
NEAR THE FIELD THEN MOVE NORTH. PREDICTABILITY AND CONFIDENCE
IS RATHER LOW FOR ANY SPECIFIC TIMING SO WILL KEEP MONITORING FOR
CONSISTENT IFR BUT DON`T WANT TO FORCE ANY HANDS FOR IFR PLANNING
BY INCLUDING A BROKEN DECK AT THIS POINT. SHOULD SEE THE THREAT
EASE WITH TIME TODAY. A MORE SOLID DECK AROUND 4 TO 6 KFT SHOULD
DEVELOP BY MID AFTERNOON ALONG WITH MORE PERSISTENT RAIN BY 00Z
THIS AFTERNOON. EXPECT TO SEE RAIN AND MVFR CIGS CONTINUE UNTIL
AFTER 26/12Z. /JBONK
&&
.MARINE...WILL SEE A WEAK SURFACE LOW SIT JUST OFFSHORE BRINGING
WIND GUSTS KNOCKING ON THE 21 KT SMALL CRAFT THRESHOLD. WILL
FOLLOW THE WHEN IN DOUBT LEAVE IT OUT PHILOSOPHY AS MODELS SHOW
DISAGREEMENT REGARD WIND STRENGTH. SEAS WILL STAY AROUND 6FT TODAY
THEN EASE BACK A BIT OVERNIGHT TONIGHT. THE WATERS WILL THEN STAY
SOMEWHAT BENIGN UNTIL MEMORIAL DAY WHEN ANOTHER PACIFIC FRONT WILL
APPROACH. IT APPEARS THAT SOLID SMALL CRAFT WINDS AND POSSIBLE
SEAS WILL ARRIVE. ONE MODEL DOES SHOW GALE GUSTS BUT IT APPEARS TO
BE AN OUTLIER AT THIS TIME. USING A MORE CONSERVATIVE APPROACH
YIELDS SEAS IN THE 6 TO 8 FT RANGE AND EVEN THEN PRIMARILY WIND
WAVE/FRESH SWELL DRIVEN. AS SUCH WILL SEE A RAPID EASING ONCE WINDS
DROP OFF MONDAY NIGHT.
STILL LOOKING FOR RATHER LARGE BAR SWELL DURING THE VERY STRONG
EBB THIS MORNING AND KEEP THE ROUGH BAR ADVISORY IN PLAY FOR THIS
MORNINGS EBB. WINDS ARE WEAKER TODAY AND CAMERAS DID NOT SHOW ANY
BREAKS YESTERDAY MORNING. THUS...WILL MENTION BREAKS ONLY AS A
POSSIBILITY DUE TO THE STRONGER FLOW. /JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 8 AM PDT
THIS MORNING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 250946
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
246 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Today through Sunday...General trof pattern continues to influence
the sensible weather over Eastern Washington and Northern Idaho
keeping it unsettled at times along with temperatures on the cool
side of what would be considered normal this time of year. Last
few HRRR model runs hit at surface based convection over the
northern mountains after 11AM PDT today and upon further inspection
GFS runs for this interval show the cold pool aloft at 500mb
helping to keep the instability overhead extends west to overhang
parts of the cascades...thus the minor mention of afternoon and
early evening thunderstorms has been stretched westward to cover
parts of the East Slopes of the Northern cascades roughly north of
Leavenworth. Models also hint at a mesoscale shortwave or two
producing enough forcing to allow for some minor mention of
showers overnight...one near the cascades and the other passing
over the Blue Mountains up into North Idaho Panhandle. Sunday the
trof overhead is very very cluttered with synoptic and mesoscale
shortwave propagation through it which allows for the mention of
showers to persist. Forecast temps show a very slight cooling
trend as the flow turns a bit more southerly, which is a warm
trajectory most of the time, for Sunday. Additionally since the
jet stream is south of the forecast area through this time
interval resulting in a lowered tropopause (down to near 400mb)
some of these showers could produce the typical early spring
precipitation type (graupel or soft hail) for a spell along with
mixing moderate wind gusts down to the surface which is something
to keep in mind over the weekend. /Pelatti
Sunday Night through Wednesday: The cool upper level trough that
has been anchored over the Pacific Northwest since Wednesday is
expected to pivot into western Montana Sunday night into Monday
bringing scattered showers to the eastern third of Washington and
northern Idaho. Despite the displacement of this upper low, our
weather pattern isn`t expected to change much. There is good
agreement between the medium range models that the Polar Jet will
dive into southern Oregon and carve another upper level trough
over the Pacific Northwest. The best jet dynamics (Q-Vector
Divergence) Monday night into Tuesday should be over southern
Oregon into the Great Basin, but there will be enough moisture and
deep layer instability with the weakening frontal occlusion to
maintain a good chance of showers Tuesday and Tuesday night.
Depending on the timing of this system, we may need to add a
mention of thunderstorms on Tuesday. The 00z GFS, Canadian and
ECMWF are in pretty good agreement with a weak, negatively tilted
trough over central and western Washington. The GFS and ECMWF
are producing precipitation that looks convectively driven over
the north Cascades. The potential for thunderstorms over the burn
scars around Wenatchee, Ellensburg, and Chelan will be a concern
through the summer and we will continue to monitor patterns like
this one closely for mudslides and debris flows.
The axis of a west to east oriented upper trough is expected to
linger over the Pacific Northwest Wednesday and through the end of
the week. It does look like Tuesday`s frontal occlusion will bring
the most widespread shower activity to the region this week, but
afternoon and early evening showers will be in the forecast for
much of the week. /GKoch
Wednesday Night through Friday Night: Through this time frame we
continue to see an unsettled pattern that will continue to feature
the chance for precipitation across most of the Inland NW
especially for the higher terrains of the ID Panhandle along with
Cascade Crests earlier in the period. Models are in pretty good
agreement through Friday Afternoon by keeping a large scale
negatively tilted trough pattern in place allowing for moisture to
flow in behind the low center that pushes to our SE throughout the
night on Wednesday. With the increased moisture, there will be
thick cloud cover keeping temps in the lower 60s and 70s for
most correlating to below normal temps for this time of year. Low
temps will follow the same pattern of a couple degrees below
normal due to the lack of daytime heating. Towards the end of the
period models are indicating a ridge builds behind the exiting
trough which should help to diminish the precipitation
threat...lower the cloud coverage and ultimately push temperatures
closer to seasonal averages as we approach next weekend. Overall
not many changes were made to the forecast..just tinkered with the
POPs slightly to reflect most recent model data and trended the
temps in the same manner. /Fliehman
&&
.AVIATION...
06Z TAFS: The Inland Northwest will be under a broad area of low
pressure through tonight. Mid to high level cloud cover is expected
over much of the region through Saturday morning. Some low level
moisture across the northern valleys and Panhandle valleys tonight
may result in some patchy fog by the morning hours. Another
relatively weak system for Saturday afternoon will produce mainly
mountain showers. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 50 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 50 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 50 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 50 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 63 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 61 44 63 46 62 47 / 40 20 30 60 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 250548
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1048 PM PDT Fri May 24 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday, then a
subtle warming and drying trend is anticipated by Monday as the
upper-level low moves out of the area. The break will be
short lived as another cool, showery pattern returns around the
middle of next week.
&&
.DISCUSSION...
Update: Three different areas of low pressure this evening will
have some degree of impact on the weather through tonight. One
low is pushing across the basin this evening into the ID
Panhandle. This system is responsible for the scattered showers
and thunderstorms that quickly developed over the Palouse earlier
this evening. This batch of showers is expected to continue to
push east with this system through the late evening hours. With
our daytime heating being the primary mechanism of instability
with this convection, I don`t expect any more lighting from these
showers now that the sun is setting.
The second area of low pressure is located over southern Alberta.
Moisture wrapping around this system is pushing across some mid
level cloud cover into the region out of Canada. Radar imagery
does show some showers with this activity. Model data also
indicates a bit more upper level instability across these northern
zones from the Okanogan Highlands over into the Northern
Panhandle. As a result, I do expect showers to continue across
these areas through the night; although, according to the HRRR
model, much of these showers will remain north of the Canadian
border.
A third area of low pressure is beginning to take shape over
Victoria BC. This area of low pressure is generating some
scattered showers west of the Cascade crest, and I expect much of
these showers will remain in western WA. This system will be the
primary forcing mechanism for more showers on Saturday as a vort
max rotates around the base of the low pressure center.
Some patchy fog was added to the forecast for late tonight into
tomorrow morning across the northern mountain valleys and across the
central Panhandle valleys. Colder temperatures and some added
moisture from today should allow these locations to saturate near
the surface under the inversion. The mid level cloud cover
approaching from the north is expected to temper the radiative
cooling tonight closer to the Canadian border; however, models
indicate that this cloud shield will remain across the northern
half of these mountain zones. So I did trim back mention of fog
away from the Canadian border a bit and mainly kept it in for
locations such as Newport, Deer Park, Fruitland and Keller. /SVH
&&
.AVIATION...
06Z TAFS: The Inland Northwest will be under a broad area of low
pressure through tonight. Mid to high level cloud cover is expected
over much of the region through Saturday morning. Some low level
moisture across the northern valleys and Panhandle valleys tonight
may result in some patchy fog by the morning hours. Another
relatively weak system for Saturday afternoon will produce mainly
mountain showers. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 63 44 65 46 68 / 20 20 10 20 10 30
Coeur d`Alene 41 63 42 65 43 67 / 20 20 20 30 10 40
Pullman 35 64 43 63 43 67 / 20 10 10 30 30 20
Lewiston 42 71 48 70 49 74 / 10 10 10 30 40 20
Colville 40 67 41 72 43 72 / 30 40 30 20 10 40
Sandpoint 40 63 39 66 41 66 / 30 30 20 20 10 40
Kellogg 41 61 44 63 45 65 / 40 40 20 30 20 40
Moses Lake 42 72 46 73 48 74 / 0 10 0 10 10 10
Wenatchee 48 68 47 70 50 71 / 10 10 10 10 10 10
Omak 39 68 41 71 44 72 / 10 30 20 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KSEW 250450
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
950 PM PDT FRI MAY 24 2013
.SYNOPSIS...AN UPPER LEVEL TROUGH IS OVER THE REGION. THIS COOL
WEATHER PATTERN WILL REMAIN IN PLACE THROUGH NEXT WEEK. A WEATHER
DISTURBANCE MOVING THROUGH THE UPPER TROUGH WILL MAINLY MOVE INTO
WESTERN OREGON SATURDAY NIGHT BUT COULD INCREASE THE SHOWER ACTIVITY
OVER WESTERN WASHINGTON BY SUNDAY MORNING. ANOTHER DISTURBANCE WILL
PROBABLY REACH THE AREA MONDAY AFTERNOON AND EVENING FOR ANOTHER
INCREASE IN SHOWERS.
&&
.SHORT TERM...THERE ARE SCATTERED SHOWERS ALONG AND JUST OFF THE
COAST AND A FEW SOUTH OF THE METRO AREA THIS EVENING. AN UPPER
TROUGH WILL REMAIN OVER THE PACIFIC NORTHWEST THROUGH THE WEEKEND.
THERE WILL BE A FEW SHOWERS AT TIMES. THE NAM SHOWS SOME PRECIP
DEVELOPING SOUTH OF SEATTLE SATURDAY NIGHT...MORE OF A DEFORMATION
ZONE WITH A PERIOD OF RAIN FOR WESTERN OREGON AND SOUTHWEST WA
SATURDAY NIGHT. THE UW WRFGFS PUSHES SOME OF THAT RAIN NORTHWARD
INTO WESTERN WA BUT STILL SOUTH OF A LINE FROM ABOUT CHEHALIS TO THE
CENTRAL CASCADES SUNDAY MORNING. ANOTHER DISTURBANCE SPREADS SOME
RAIN TO THE COAST AROUND DAYBREAK MONDAY...AND SOME SHOWERS INTO THE
INTERIOR OF WESTERN WA MONDAY AFTERNOON AND NIGHT. HE GFS IS SLOWER
WITH THAT...IT HAS SOME RAIN TO THE COAST MON AFTERNOON AND INTO THE
INTERIOR OF WESTERN WA MONDAY NIGHT.
.LONG TERM...NEXT WEEK WILL BE COOL AND UNSETTLED WITH AN UPPER
TROUGH STILL OVER THE REGION. THERE WILL BE A GOOD CHANCE OF SHOWERS
AT TIMES WITH CONTINUED BELOW NORMAL TEMPS.
&&
.AVIATION...WEAK UPPER LEVEL LOW REMAINING OVER WESTERN WASHINGTON
THROUGH SATURDAY WITH LIGHT LOW LEVEL FLOW. AIR MASS MOIST AND
SLIGHTLY UNSTABLE.
WIDE VARIETY OF CEILINGS WILL CONTINUE OVER THE AREA THROUGH
SATURDAY. IN GENERAL...CEILINGS IN THE 4000 TO 6000 FOOT RANGE WITH
CEILINGS AS LOW AS 1500 FEET NEAR SHOWERS. CEILINGS LOWERING IN THE
12Z-18Z TIME FRAME AROUND 3000 TO 4000 FEET WITH CONTINUED LOWER
CEILINGS IN THE VICINITY OF SHOWERS.
KSEA...S WIND 6 TO 10 KNOTS FOR NEXT 24 HOURS. MAINLY VFR CIGS
EXPECTED...DROPPING TO MVFR BRIEFLY DURING SHOWERS. FELTON
&&
.MARINE...SMALL CRAFT ADVISORY FOR THE CENTRAL STRAIT WILL COME TO
AN END OVERNIGHT AS GRADIENTS WEAKEN. LIGHT GRADIENTS LATER TONIGHT
INTO SATURDAY. WEAK SURFACE LOW OVER THE OFFSHORE WATERS
TONIGHT WILL MOVE SOUTHEAST AND DISSIPATE ON SATURDAY WITH ONSHORE
FLOW DEVELOPING ON SUNDAY. THE NEXT ORGANIZED FRONT REACHES THE
WATERS ON MONDAY WITH SMALL CRAFT WINDS PROBABLE OVER THE COASTAL
WATERS. FELTON
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR CENTRAL AND EASTERN STRAIT FROM 5 PM
PDT UNTIL LATE TONIGHT.
&&
$$
000
FXUS66 KOTX 250406
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
906 PM PDT Fri May 24 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday, then a
subtle warming and drying trend is anticipated by Monday as the
upper-level low moves out of the area. The break will be
short lived as another cool, showery pattern returns around the
middle of next week.
&&
.DISCUSSION...
Update: Three different areas of low pressure this evening will
have some degree of impact on the weather through tonight. One
low is pushing across the basin this evening into the ID
Panhandle. This system is responsible for the scattered showers
and thunderstorms that quickly developed over the Palouse earlier
this evening. This batch of showers is expected to continue to
push east with this system through the late evening hours. With
our daytime heating being the primary mechanism of instability
with this convection, I don`t expect any more lighting from these
showers now that the sun is setting.
The second area of low pressure is located over southern Alberta.
Moisture wrapping around this system is pushing across some mid
level cloud cover into the region out of Canada. Radar imagery
does show some showers with this activity. Model data also
indicates a bit more upper level instability across these northern
zones from the Okanogan Highlands over into the Northern
Panhandle. As a result, I do expect showers to continue across
these areas through the night; although, according to the HRRR
model, much of these showers will remain north of the Canadian border.
A third area of low pressure is beginning to take shape over
Victoria BC. This area of low pressure is generating some
scattered showers west of the Cascade crest, and I expect much of
these showers will remain in western WA. This system will be the
primary forcing mechanism for more showers on Saturday as a vort
max rotates around the base of the low pressure center.
Some patchy fog was added to the forecast for late tonight into
tomorrow morning across the northern mountain valleys and across the
central Panhandle valleys. Colder temperatures and some added
moisture from today should allow these locations to saturate near
the surface under the inversion. The mid level cloud cover
approaching from the north is expected to temper the radiative
cooling tonight closer to the Canadian border; however, models
indicate that this cloud shield will remain across the northern
half of these mountain zones. So I did trim back mention of fog
away from the Canadian border a bit and mainly kept it in for
locations such as Newport, Deer Park, Fruitland and Keller. /SVH
&&
.AVIATION...
00Z TAFS: Energy moving around a low pressure center will allow
scattered showers to continue this evening, with a chance of
thunderstorms. Expect primarily VFR conditions but local MVFR or
IFR cigs are possible with passing showers. The threat of showers
will wane after dark. Scattered showers and isolated thunderstorms
will develop again Saturday afternoon but confidence in location
of showers is too low to put in TAFs. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 63 44 65 46 68 / 20 20 10 20 10 30
Coeur d`Alene 41 63 42 65 43 67 / 20 20 20 30 10 40
Pullman 35 64 43 63 43 67 / 20 10 10 30 30 20
Lewiston 42 71 48 70 49 74 / 10 10 10 30 40 20
Colville 40 67 41 72 43 72 / 30 40 30 20 10 40
Sandpoint 40 63 39 66 41 66 / 30 30 20 20 10 40
Kellogg 41 61 44 63 45 65 / 40 40 20 30 20 40
Moses Lake 42 72 46 73 48 74 / 0 10 0 10 10 10
Wenatchee 48 68 47 70 50 71 / 10 10 10 10 10 10
Omak 39 68 41 71 44 72 / 10 30 20 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KPQR 250343
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
843 PM PDT FRI MAY 24 2013
.SYNOPSIS...A PIECE OF THE LOW THAT BROUGHT COPIOUS RAIN TO SOUTHWEST
WASHINGTON AND NORTHWEST OREGON WILL REMAIN CENTERED ALONG THE
WASHINGTON COAST TONIGHT AND SATURDAY MORNING THEN MOVE OFF TO THE
NORTHEAST. THIS WILL BE FOLLOWED BY ANOTHER LOW DROPPING IN FROM THE
NORTHWEST AND OFF THE PACIFIC LATER SATURDAY AND SATURDAY NIGHT FOR
MORE PRECIPITATION. THIS LOW WILL LINGER IN THE AREA SUNDAY BEFORE
MOVING EAST SUNDAY NIGHT. THE NEXT DECENT FRONT APPEARS THAT IT WILL
MOVE INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON ON MEMORIAL DAY
MONDAY. A MOSTLY WESTERLY FLOW WILL KEEP THINGS UNSETTLED WITH SOME
PRECIPITATION AT TIMES NEXT WEEK.
&&
.SHORT TERM...DID GET SOME DECENT SHOWERS ACROSS THE NORTHERN PART OF
OUR FORECAST AREA THIS AFTERNOON AND EVENING. MODEL DATA SHOWED
INSTABILITY UP THROUGH 700 MB BUT IT WAS CAPPED AT 600 AND 500 MB...
THUS THE SHOWERS WERE STILL VIGOROUS BUT NOT DEEP ENOUGH TO PRODUCE
CHARGE SEPARATION AND ANY LIGHTNING. SHOWERS ARE MOSTLY MOVING INTO
THE CASCADES AND DECREASING THIS EVENING...AND SHOULD CONTINUE TO
DECREASE OVERNIGHT.
NEXT UP IS A LOW OR CIRCULATION CENTER THAT IS CENTERED AROUND
48N/133W AND HEADING SOUTHEAST TOWARD SOUTHWEST WASHINGTON AND
NORTHWEST OREGON. SHOULD SEE SOME INCREASE IN PRECIPITATION THROUGH
THE DAY SATURDAY FROM THE WEST...WITH A PEAK SATURDAY NIGHT AS THIS
LOW MOVES ONSHORE. THE LOW IS STILL OVERHEAD OR NEARBY MUCH OF
SUNDAY...SO WE SHOULD SEE A DECENT AMOUNT OF SHOWERS. THE AIR ALOFT
MAY GET COOL ENOUGH WE MIGHT TRIGGER A THUNDERSTORM OR TWO SUNDAY
AFTERNOON.
SHOWERS SHOULD DECREASE SUNDAY NIGHT AS THIS LOW MOVES OFF TO THE
EAST. THE NEXT MORE PROGRESSIVE AND ORGANIZED PACIFIC COLD FRONT IS
EXPECTED TO MOVE IN ON MEMORIAL DAY MONDAY FOR INCREASING RAIN. SNOW
LEVELS WILL BE 7000 TO 8000 FEET WITH THIS FRONT. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MODELS START OUT IN GOOD AGREEMENT DURING THE EXTENDED PERIOD MON
NIGHT AND TUE...WITH A TROUGH PUSHING INLAND OVER THE WEST COAST.
MOST OF THE ENERGY APPEARS HEADED S OF THE FORECAST AREA TOWARDS CA.
AS THE NORTHERN STREAM APPEARS TO REMAIN AN OPEN WAVE...WILL BOOST
POPS INTO LIKELY CATEGORY. MODELS DIVERGE SOME LATER IN THE WEEK...
BUT KEEP A COMMON THEME OF SHORTWAVES PUSHING IN IN A WESTERLY FLOW
ALOFT. WILL KEEP POPS RELATIVELY HIGH FOR A SYSTEM ON WED...BUT THEN
WILL DROP POPS OFF LATER IN THE WEEK AS UPPER HEIGHTS RISE.
&&
.AVIATION...A WEAK TROUGH WILL CONTINUE OVER THE AREA TONIGHT WITH A
FEW SHOWERS CONTINUING. SATURDAY MORNING A WEAK BUT FAIRLY MOIST
SYSTEM WILL NEAR THE COAST. CURRENT MODELS INDICATING MAIN FOCUS OF
THE PCPN IS TO THE SOUTH PORTION OF THE FCST AREA. FOR THE COAST...
MAINLY VFR TO START BUT MVFR BECOMING LIKELY. AN ORGANIZED BAND OF
SHOWERS EXTEND OFF THE COAST FROM AROUND NEWPORT GIVING IFR
CONDITIONS THERE. CONDITIONS MAY IMPROVE 05Z TO 07Z FROM IFR TO MVFR
AS THE BAND SHIFTS NORTH. INLAND AREAS...FEW SHOWERS AROUND THOUGH
VFR CONDITIONS PREVAILING THIS EVENING. CONDITIONS BECOMING MORE
STABLE OVERNIGHT PER MODEL SOUNDINGS TRAPPING LOWER LEVEL MOISTURE
FOR INCREASING CHANCES OF MVFR CIGS DEVELOPING AFTER 12Z. BUT BY 18Z
OR SO CONDITIONS GENERALLY VFR BUT TENDING TO MVFR LATE SAT AFTERNOON
OR EVENING AS THE NEXT FRONT APPROACHES.
KPDX AND APPROACHES...VFR WITH A FEW SHOWERS EXPECTED THROUGH THE
NIGHT. STATISTICAL GUIDANCE AND MODEL SOUNDINGS SPLIT ON MVFR IN THE
AREA SAT MORNING SO WILL NOT INCLUDE MVFR AT THIS TIME.
&&
.MARINE...SEAS WILL REMAIN AROUND 6 FT THROUGH SUN. ANOTHER WEAK
SYSTEM PUSHES INTO THE WATERS EARLY ON SATURDAY...PROVIDING BREEZY
WINDS BY SATURDAY AFTERNOON BUT WINDS ARE EXPECTED TO REMAIN BELOW 20
KT. A MORE ORGANIZED SYSTEM IS EXPECTED ON MONDAY WHICH COULD PRODUCE
A BRIEF COASTAL JET FOR GUSTS 30 TO 35 KT...BUT THIS DEPENDS ON THE
TRACK. THERE IS STILL SOME POSSIBILITY THIS SYSTEM COULD FOCUS MORE
ON SRN OREGON AND NRN CALIFORNIA THAN OUR WATERS.
MORNING EBBS REMAIN VERY STRONG DUE TO THE FULL MOON...SO EXPECT
ROUGH COLUMBIA RIVER BAR CONDITIONS THE NEXT COUPLE MORNINGS.
BURGESS/WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
4 AM TO 8 AM PDT SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 242338
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
438 PM PDT Fri May 24 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday, then a
subtle warming and drying trend is anticipated by Monday as the
upper-level low moves out of the area. The break will be
short lived as another cool, showery pattern returns around the
middle of next week.
&&
.DISCUSSION...
Tonight and Saturday: Lots going on this afternoon. Mostly clear
skies this morning across northern WA and ID have given way to
afternoon showers and thunderstorms. An upper level low is
currently just south of Moses Lake. It brought a band of wrap around
showers to central WA earlier this morning and it has finally
stretched and sheared apart as it trucked north towards Spokane.
Behind this thicker band of clouds from the wrap around precip,
cumulus clouds and subsequent showers have developed. Basically,
there is a chance of showers just about everywhere late this
afternoon and early this evening. You yourself may not get rained
on, but if you were to look out you would see showers all around
you. Isolated thunderstorms have developed in association with the
showers with a chance of them just about everywhere, exactly like
the showers. Models are showing showers and thunderstorms
decreasing through the evening hours as the low shifts northeast
into northwest Montana. Another low is developing off the
northwest WA coast and will shift into WA Saturday. Showers are
expected to develop again by afternoon...this time mainly north of
Highway 2. Temperatures tonight and Sat will be predominately
below average for this time of the year. Temperatures will be
above freezing though tonight. The exception to this will be
across the mountains in the north. /Nisbet
Saturday night through Monday...The unsettled weather pattern will
continue through the weekend...however the models are still having
trouble fine tuning the small scale features. The upper level low
will remain over the Pacific Northwest and B.C. through
Monday...with a reinforcing secondary low dumb belling around the
main low Saturday night and Sunday...and a much stronger trough
coming off the Pacific Monday night and Tuesday. A new surge of
moisture will be associated with each of these waves...but mostly
around the periphery of the wave. With the cold core right over
the forecast area there will be a chance of light showers just
about anywhere...but I tried to time the best chances of
precipitation with each incoming wave. Lingering showers will be
possible Saturday night across the northern zones. The focus then
shifts to the southeast and eastern zones for Sunday afternoon and
again Monday afternoon where the models are showing the best
instability and forcing. There may be a chance for isolated
lightning strikes with the wave on Sunday in the vicinity of the
Blues and the Camas Prairie. Temperatures will remain on the cool
side of normal. /Tobin
Monday night through Friday...Somewhat cool and unsettled conditions
will prevail throughout the extended forecast period while the
region remains under an upper level trough. Model consensus is fair
with latest run of the GFS/DGEX/GEM showing similar solutions but
the 12Z ECMWF takes the upper low on a different course of evolution.
Rather than the agreed on solution of a negatively tilted trough
extending NW to SE over the forecast area, the EC splits the flow
and drops a closed low into the Great Basin. This would lower the
chance of precipitation over our northeast zones, which is precisely
where the other models bring the focus for higher PoPs. I trended
the northeast down slightly, but for the most part, Pops remain
above climo, with temperatures on the cool side of normal. I did
introduce a slight chance of thunder for portions of the Idaho zones
on Tuesday as the trough axis moves inland. Any significant changes
will wait for better consensus. /Kelch
&&
.AVIATION...
00Z TAFS: Energy moving around a low pressure center will allow
scattered showers to continue this evening, with a chance of
thunderstorms. Expect primarily VFR conditions but local MVFR or
IFR cigs are possible with passing showers. The threat of showers
will wane after dark. Scattered showers and isolated thunderstorms
will develop again Saturday afternoon but confidence in location
of showers is too low to put in TAFs. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 42 63 44 65 46 68 / 40 20 10 20 10 30
Coeur d`Alene 42 63 42 65 43 67 / 50 20 20 30 10 40
Pullman 38 64 43 63 43 67 / 20 10 10 30 30 20
Lewiston 43 71 48 70 49 74 / 20 10 10 30 40 20
Colville 40 67 41 72 43 72 / 60 40 30 20 10 40
Sandpoint 41 63 39 66 41 66 / 60 30 20 20 10 40
Kellogg 41 61 44 63 45 65 / 60 40 20 30 20 40
Moses Lake 45 72 46 73 48 74 / 20 10 0 10 10 10
Wenatchee 48 68 47 70 50 71 / 20 10 10 10 10 10
Omak 40 68 41 71 44 72 / 40 30 20 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KPQR 242330
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
240 PM PDT FRI MAY 24 2013
.SYNOPSIS...AN UPPER LOW OVER EASTERN WA FRI AFTERNOON WILL WEAKEN
THIS WEEKEND AS IT LIFTS NE INTO ALBERTA. A FEW DISTURBANCES WILL
CONTINUE TO ROTATE AROUND THE LOW...KEEPING A THREAT OF SHOWERS IN
THROUGH THE WEEKEND WITH TEMPERATURES WARMING A BIT CLOSER TO
NORMAL. AN ACTIVE PATTERN WILL CONTINUE NEXT WEEK AS THE FLOW TURNS
WESTERLY...AND A SERIES OF WEAK DISTURBANCES COME IN OFF THE
PACIFIC.
&&
.SHORT TERM...RADAR AND SURFACE OBSERVATIONS HAVE SHOWN SHOWERS
TODAY LARGELY CONFINED TO THE MOUNTAINS TODAY. THE UPPER LOW HAS
BEGUN TO SHIFT E...TOWARDS EASTERN WA...AND IS EXPECT TO CONTINUE NE
TONIGHT AND SAT. THERE ARE STILL SOME SHORTWAVES EXPECTED TO ROTATE
AROUND THE LOW...AND DROP DOWN THE BACKSIDE OF THE LOW THIS
WEEKEND...KEEPING SOME THREAT FOR SHOWERS IN. THE MAIN SHORTWAVE
APPEARS TO ONE DIGGING S OFF THE COAST SAT NIGHT AND SUN. WITH THE
BEST DYNAMICS DIGGING S...WILL SHOW THE HIGHEST POPS ACROSS THE
SOUTHERN PART OF THE FORECAST AREA SAT NIGHT AND SUN.
MODELS ALL SUGGESTING SOME BREAK BETWEEN SYSTEMS LATE SUN NIGHT AND
EARLY MON. AFTER WEAK RIDGING ALOFT THEN...THE FIRST SYSTEM IN THE
DEVELOPING WESTERLY FLOW OFF THE PACIFIC APPROACHES MON. THIS SYSTEM
TOO APPEARS LIKELY TO SEND ITS MAIN ENERGY ACROSS THE S PART OF THE
FORECAST AREA. WITH FAIRLY DEEP MOISTURE...WILL BUMP POPS UP TO
CATEGORICAL FOR LAT MON IN THE S...TAPERING TO CHANCE POPS IN THE
FAR NE CORNER.
.LONG TERM...MODELS START OUT IN GOOD AGREEMENT DURING THE EXTENDED
PERIOD MON NIGHT AND TUE...WITH A TROUGH PUSHING INLAND OVER THE
WEST COAST. MOST OF THE ENERGY APPEARS HEADED S OF THE FORECAST AREA
TOWARDS CA. AS THE NORTHERN STREAM APPEARS TO REMAIN AN OPEN
WAVE...WILL BOOST POPS INTO LIKELY CATEGORY. MODELS DIVERGE SOME
LATER IN THE WEEK...BUT KEEP A COMMON THEME OF SHORTWAVES PUSHING IN
IN A WESTERLY FLOW ALOFT. WILL KEEP POPS RELATIVELY HIGH FOR A
SYSTEM ON WED...BUT THEN WILL DROP POPS OFF LATER IN THE WEEK AS
UPPER HEIGHTS RISE.
&&
.AVIATION...WEAK SURFACE LOW LINGERING OFFSHORE WILL BE SLOW TO MOVE
OUT OF THE AREA THIS EVENING. THIS HAS KEPT THE REGION IN A MOIST
AIR MASS WITH WEAK FLOW ALOFT. THEREFORE SHOWERS AND LOCAL IFR/LOW
MVFR CIGS HAVE REMAINED AT THE COAST...WHILE INLAND VFR WITH AREAS
OF MVFR WILL CONTINUE THROUGH LATE AFTERNOON. SHOWERS BEGIN TO
DIMINISH AFTER 00Z AS THE SURFACE FLOW BECOMES MORE
SOUTHWESTERLY...WHILE A DRY LAYER PUSHES INTO THE MID-LEVELS. THIS
DRY LAYER WILL HELP TRAP MOISTURE IN THE LOWER LEVELS...FOR SLOWLY
LOWERING CIGS OVERNIGHT. ANOTHER SYSTEM WILL USHER RAIN AND LOW CIGS
INTO THE AREA BEGINNING LATE TOMORROW MORNING.
KPDX AND APPROACHES...EXPECT MVFR IN SHOWERS TO PREVAIL THROUGH
AROUND 00Z...WITH PERIODS OF VFR BETWEEN SHOWERS. VFR SHOULD
PREVAIL AFTER 00Z AS SHOWER COVERAGE RAPIDLY DECREASES. AFTER 06Z
CIGS WILL SLOWLY LOWER BACK TO MVFR...WITH LIGHT DRIZZLE POSSIBLE
OVERNIGHT. BREEZY SURFACE WINDS WILL DIMINISH BY 03Z.
&&
.MARINE...FEW UPDATES NEEDED. SEAS WILL REMAIN AROUND 7-8 FT
THROUGH THIS EVENING...BEFORE RELAXING TO NEAR 6 FT TONIGHT. SEAS
WILL CONTINUE TO EASE SATURDAY AND REMAIN LESS THAN 6 FT THROUGH
SUNDAY. ANOTHER WEAK SYSTEM PUSHES INTO THE WATERS EARLY ON
SATURDAY...PROVIDING BREEZY WINDS BY SATURDAY AFTERNOON BUT WINDS
ARE EXPECTED TO REMAIN BELOW 20 KT. A MORE ORGANIZED SYSTEM IS
EXPECTED ON MONDAY WHICH COULD PRODUCE A BRIEF COASTAL JET FOR
GUSTS 30 TO 35 KT...BUT THIS DEPENDS ON THE TRACK. THERE IS STILL
SOME POSSIBILITY THIS SYSTEM COULD FOCUS MORE ON SRN OREGON AND
NRN CALIFORNIA THAN OUR WATERS.
MORNING EBBS REMAIN VERY STRONG DUE TO THE FULL MOON...SO EXPECT
ROUGH COLUMBIA RIVER BAR CONDITIONS THE NEXT COUPLE MORNINGS.
BURGESS/WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
4 AM TO 8 AM PDT SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KSEW 242206
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
306 PM PDT FRI MAY 24 2013
.SYNOPSIS...A WEAKENING LOW PRESSURE SYSTEM WILL REMAIN OVER THE
REGION THROUGH THIS WEEKEND BUT THERE WILL BE A TREND TOWARD LESS
SHOWERS...MORE SUNSHINE...AND WARMER AFTERNOON TEMPERATURES. ANOTHER
UPPER LOW WILL MAINLY IMPACT THE SOUTHWEST PART OF THE STATE ON
MEMORIAL DAY.
&&
.SHORT TERM...
THERE WERE SCATTERED SHOWERS...MORE NUMEROUS OVER THE SOUTHWEST
HALF...PRESENT OVER THE FORECAST AREA THIS AFTERNOON. MUCH OF THIS
ACTIVITY WILL DISSIPATE THIS EVENING.
AN UPPER LOW WILL REMAIN OVER THE PACIFIC NORTHWEST THROUGH THIS
WEEKEND BUT WILL GRADUALLY FILL AND WEAKEN WITH TIME. THIS WILL
RESULT IN A TREND TOWARD LESS SHOWERS...MORE SUNSHINE...AND WARMER
AFTERNOON TEMPERATURES.
THE UPPER TROF WILL MOVE EAST OF THE AREA LATE SUNDAY NIGHT OR EARLY
MON. HOWEVER ANOTHER UPPER LOW IS EXPECTED TO DIG OFF THE COAST ON
MEMORIAL DAY. THIS SYSTEM WILL HEAD TOWARD OREGON...THEREFORE THE
BEST CHANCE OF PRECIP WILL LIKELY BE OVER THE SOUTHWEST PORTION OF
THE CWA. WENT ON AHEAD AND REMOVED THE THREAT OF PRECIP FROM MUCH OF
THE NORTHEAST HALF OF THE FORECAST AREA.
.LONG TERM...
MUCH OF THIS PERIOD WILL BE UNSETTLED DUE TO A NEGATIVE TILTED UPPER
TROF OVER THE REGION. THUS ANTICIPATE A RISK OF PRECIP...ESPECIALLY
THE MIDDLE OF NEXT WEEK...AND GENERALLY BELOW NORMAL DAYTIME
TEMPS.
&&
.AVIATION...AN UPPER LEVEL TROUGH OVER WA WILL CONTINUE TO MIGRATE
EASTWARD...ENTERING EASTERN WA BY THIS EVENING. SOUTHERLY FLOW
CURRENTLY OVER WESTERN WA WILL CONTINUE INTO TOMORROW. MOIST AND
SLIGHTLY UNSTABLE. SCATTERED SHOWERS...MOSTLY WEST OF THE
SOUND...WILL DECREASE IN NUMBER BY TONIGHT. LESS THAN A 10 PERCENT
CHANCE OF ISOLATED THUNDERSTORMS THIS AFTERNOON/EARLY EVENING.
KSEA...S WIND 5 TO 8 KT FOR NEXT 24 HOURS. MAINLY VFR CIGS
EXPECTED...DROPPING TO MVFR DURING SHOWERS.
&&
.MARINE...LIGHTER GRADIENTS AND WINDS OVER MOST WA WATERS TODAY.
WEAK ONSHORE FLOW WILL INCREASE A BIT TONIGHT THROUGH THE WEEKEND.
EXPECTING SMALL CRAFT ADVISORY WINDS TO DEVELOP LATE THIS AFTERNOON
IN THE CENTRAL AND EASTERN STRAIT...THUS AN ADVISORY IS IN PLACE.
THE NEXT ORGANIZED FRONT REACHES THE WATERS ON MONDAY WITH SMALL
CRAFT WINDS PROBABLE OVER THE COASTAL WATERS.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 2 AM PDT SATURDAY FOR
THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
FOR THE GRAPHICAL AFD...VISIT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
000
FXUS66 KPQR 242142
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
240 PM PDT FRI MAY 24 2013
.SYNOPSIS...AN UPPER LOW OVER EASTERN WA FRI AFTERNOON WILL WEAKEN
THIS WEEKEND AS IT LIFTS NE INTO ALBERTA. A FEW DISTURBANCES WILL
CONTINUE TO ROTATE AROUND THE LOW...KEEPING A THREAT OF SHOWERS IN
THROUGH THE WEEKEND WITH TEMPERATURES WARMING A BIT CLOSER TO
NORMAL. AN ACTIVE PATTERN WILL CONTINUE NEXT WEEK AS THE FLOW TURNS
WESTERLY...AND A SERIES OF WEAK DISTURBANCES COME IN OFF THE
PACIFIC.
&&
.SHORT TERM...RADAR AND SURFACE OBSERVATIONS AHVE SHOWN SHOWERS
TODAY LARGELY CONFINED TO THE MOUNTAINS TODAY. THE UPPER LOW HAS
BEGUN TO SHIFT E...TOWARDS EASTERN WA...AND IS EXPECT TO CONTINUE NE
TONIGHT AND SAT. THERE ARE STILL SOME SHORTWAVES EXPECTED TO ROTATE
AROUND THE LOW...AND DROP DOWN THE BACKSIDE OF THE LOW THIS
WEEKEND...KEEPING SOME THREAT FOR SHOWERS IN. THE MAIN SHORTWAVE
APPEARS TO ONE DIGGING S OFF THE COAST SAT NIGHT AND SUN. WITH THE
BEST DYNAMICS DIGGING S...WILL SHOW THE HIGHEST POPS ACROSS THE
SOUTHERN PART OF THE FORECAST AREA SAT NIGHT AND SUN.
MODELS ALL SUGGESTING SOME BREAK BETWEEN SYSTEMS LATE SUN NIGHT AND
EARLY MON. AFTER WEAK RIDGING ALOFT THEN...THE FIRST SYSTEM IN THE
DEVELOPING WESTERLY FLOW OFF THE PACIFIC APPROACHES MON. THIS SYSTEM
TOO APPEARS LIKELY TO SEND ITS MAIN ENERGY ACROSS THE S PART OF THE
FORECAST AREA. WITH FAIRLY DEEP MOISTURE...WILL BUMP POPS UP TO
CATEGORICAL FOR LAT MON IN THE S...TAPERING TO CHANCE POPS IN THE
FAR NE CORNER.
.LONG TERM...MODELS START OUT IN GOOD AGREEMENT DURING THE EXTENDED
PERIOD MON NIGHT AND TUE...WITH A TROUGH PUSHING INLAND OVER THE
WEST COAST. MOST OF THE ENERGY APPEARS HEADED S OF THE FORCAST AREA
TOWARDS CA. AS THE NORTHERN STREAM APPEARS TO REMAIN AN OPEN
WAVE...WILL BOOST POPS INTO LIKELY CATEGORY. MODELS DIVERGE SOME
LATER IN THE WEEK...BUT KEEP A COMMON THEME OF SHORTWAVES PUSHING IN
IN A WESTERLY FLOW ALOFT. WILL KEEP POPS RELATIVELY HIGH FOR A
SYSTEM ON WED...BUT THEN WILL DROP POPS OFF LATER IN THE WEEK AS
UPPER HEIGHTS RISE.
&&
.AVIATION...WEAK SURFACE LOW LINGERING OFFSHORE WILL BE SLOW TO MOVE
OUT OF THE AREA THIS EVENING. THIS HAS KEPT THE REGION IN A MOIST
AIR MASS WITH WEAK FLOW ALOFT. THEREFORE SHOWERS AND LOCAL IFR/LOW
MVFR CIGS HAVE REMAINED AT THE COAST...WHILE INLAND VFR WITH AREAS
OF MVFR WILL CONTINUE THROUGH LATE AFTERNOON. SHOWERS BEGIN TO
DIMINISH AFTER 00Z AS THE SURFACE FLOW BECOMES MORE
SOUTHWESTERLY...WHILE A DRY LAYER PUSHES INTO THE MID-LEVELS. THIS
DRY LAYER WILL HELP TRAP MOISTURE IN THE LOWER LEVELS...FOR SLOWLY
LOWERING CIGS OVERNIGHT. ANOTHER SYSTEM WILL USHER RAIN AND LOW CIGS
INTO THE AREA BEGINNING LATE TOMORROW MORNING.
KPDX AND APPROACHES...EXPECT MVFR IN SHOWERS TO PREVAIL THROUGH
AROUND 00Z...WITH PERIODS OF VFR BETWEEN SHOWERS. VFR SHOULD
PREVAIL AFTER 00Z AS SHOWER COVERAGE RAPIDLY DECREASES. AFTER 06Z
CIGS WILL SLOWLY LOWER BACK TO MVFR...WITH LIGHT DRIZZLE POSSIBLE
OVERNIGHT. BREEZY SURFACE WINDS WILL DIMINISH BY 03Z.
&&
.MARINE...FEW UPDATES NEEDED. SEAS WILL REMAIN AROUND 7-8 FT
THROUGH THIS EVENING...BEFORE RELAXING TO NEAR 6 FT TONIGHT. SEAS
WILL CONTINUE TO EASE SATURDAY AND REMAIN LESS THAN 6 FT THROUGH
SUNDAY. ANOTHER WEAK SYSTEM PUSHES INTO THE WATERS EARLY ON
SATURDAY...PROVIDING BREEZY WINDS BY SATURDAY AFTERNOON BUT WINDS
ARE EXPECTED TO REMAIN BELOW 20 KT. A MORE ORGANIZED SYSTEM IS
EXPECTED ON MONDAY WHICH COULD PRODUCE A BRIEF COASTAL JET FOR
GUSTS 30 TO 35 KT...BUT THIS DEPENDS ON THE TRACK. THERE IS STILL
SOME POSSIBILITY THIS SYSTEM COULD FOCUS MORE ON SRN OREGON AND
NRN CALIFORNIA THAN OUR WATERS.
MORNING EBBS REMAIN VERY STRONG DUE TO THE FULL MOON...SO EXPECT
ROUGH COLUMBIA RIVER BAR CONDITIONS THE NEXT COUPLE MORNINGS.
BURGESS/WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
4 AM TO 8 AM PDT SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 242128
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
228 PM PDT Fri May 24 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday, then a
subtle warming and drying trend is anticipated by Monday as the
upper-level low moves out of the area. The break will be
short lived as another cool, showery pattern returns around the
middle of next week.
&&
.DISCUSSION...
Tonight and Saturday: Lots going on this afternoon. Mostly clear
skies this morning across northern WA and ID have given way to
afternoon showers and thunderstorms. An upper level low is
currently just south of Moses Lake. It brought a band of wrap around
showers to central WA earlier this morning and it has finally
stretched and sheared apart as it trucked north towards Spokane.
Behind this thicker band of clouds from the wrap around precip,
cumulus clouds and subsequent showers have developed. Basically,
there is a chance of showers just about everywhere late this
afternoon and early this evening. You yourself may not get rained
on, but if you were to look out you would see showers all around
you. Isolated thunderstorms have developed in association with the
showers with a chance of them just about everywhere, exactly like
the showers. Models are showing showers and thunderstorms
decreasing through the evening hours as the low shifts northeast
into northwest Montana. Another low is developing off the
northwest WA coast and will shift into WA Saturday. Showers are
expected to develop again by afternoon...this time mainly north of
Highway 2. Temperatures tonight and Sat will be predominately
below average for this time of the year. Temperatures will be
above freezing though tonight. The exception to this will be
across the mountains in the north.
Saturday night through Monday...The unsettled weather pattern will
continue through the weekend...however the models are still having trouble
fine tuning the small scale features. The upper level low will
remain over the Pacific Northwest and B.C. through Monday...with a
reinforcing secondary low dumb belling around the main low Saturday night
and Sunday...and a much stronger trough coming off the Pacific
Monday night and Tuesday. A new surge of moisture will be
associated with each of these waves...but mostly around the
periphery of the wave. With the cold core right over the forecast
area there will be a chance of light showers just about
anywhere...but I tried to time the best chances of precipitation
with each incoming wave. Lingering showers will be possible
Saturday night across the northern zones. The focus then shifts to
the southeast and eastern zones for Sunday afternoon and again
Monday afternoon where the models are showing the best instability
and forcing. There may be a chance for isolated lightning strikes
with the wave on Sunday in the vicinity of the Blues and the Camas
Prairie. Temperatures will remain on the cool side of normal.
/Tobin
Monday night through Friday...Somewhat cool and unsettled conditions
will prevail throughout the extended forecast period while the
region remains under an upper level trough. Model consensus is fair
with latest run of the GFS/DGEX/GEM showing similar solutions but
the 12Z ECMWF takes the upper low on a different course of evolution.
Rather than the agreed on solution of a negatively tilted trough
extending NW to SE over the forecast area, the EC splits the flow
and drops a closed low into the Great Basin. This would lower the
chance of precipitation over our northeast zones, which is precisely
where the other models bring the focus for higher PoPs. I trended
the northeast down slightly, but for the most part, Pops remain
above climo, with temperatures on the cool side of normal. I did
introduce a slight chance of thunder for portions of the Idaho zones
on Tuesday as the trough axis moves inland. Any significant changes
will wait for better consensus. /Kelch
&&
.AVIATION...
18Z TAFS: Low pressure and energy moving around it will push a swath
of precipitation across eastern WA and central ID panhandle this
morning. It is expected to weaken as it pushes north, but the still
approaching upper disturbance and daytime heating will help develop
other scattered showers this afternoon and evening, with a chance of
thunderstorms. Expect primarily VFR conditions but local MVFR or IFR
cigs are possible. The threat of showers will wane after
dark.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 42 63 44 65 46 68 / 40 20 10 20 10 30
Coeur d`Alene 42 63 42 65 43 67 / 50 20 20 30 10 40
Pullman 38 64 43 63 43 67 / 20 10 10 30 30 20
Lewiston 43 71 48 70 49 74 / 20 10 10 30 40 20
Colville 40 67 41 72 43 72 / 60 40 30 20 10 40
Sandpoint 41 63 39 66 41 66 / 60 30 20 20 10 40
Kellogg 41 61 44 63 45 65 / 60 40 20 30 20 40
Moses Lake 45 72 46 73 48 74 / 20 10 0 10 10 10
Wenatchee 48 68 47 70 50 71 / 20 10 10 10 10 10
Omak 40 68 41 71 44 72 / 40 30 20 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 241740
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1040 AM PDT Fri May 24 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday, then a
subtle warming and drying trend is anticipated by Monday as the
upper-level low moves out of the area. The break will be
short lived as another cool, showery pattern returns around the
middle of next week.
&&
.DISCUSSION...
Today and tonight: An upper low and the shortwave pivoting around
it will provide a good chance of showers for the Inland Northwest,
especially this afternoon. The low and its associated shortwave
disturbance were tracking through Portland, Oregon this morning.
It was helping to generate the swath of precipitation along the
west and central WA/OR border and it was starting to reach toward
the Chelan-Grant-Adams-Garfield county borders.
Satellite/radar extrapolation and models are in good agreement in
tracking the low into the lower Columbia Basin later this morning,
before it pivots northeast through the Blue Mountains through
central Panhandle of ID this afternoon and early evening. This
will allow the swath of precipitation to continue it expansion
east and northeast. Coverage increases through the afternoon, with
the added threat of thunderstorms, working with the increased
convective instability with daytime heating. On average models
depict 100-200 J/kg of CAPE this afternoon and early evening,
before conditions begin to stabilize with the loss of daytime
heating.
The lack of strong lift and/or 0-6km shear suggests that any
thunderstorms that develop should not be too organized. The
exception lays around the Blue Mountains, Camas Prairie into the
Clearwaters where 30-60kts of shear are indicated. A few stronger
storms are possible here in the afternoon and evening. The
limiting factor may be cloud cover which could inhibit the
atmosphere from reaching it full convective potential.
After dark the threat of precipitation wanes, but doesn`t entirely
end and skies do not appear to clear completely as models string a
secondary weaker vorticity lobe in from the west. The primary
shower threat linger in the Cascades and northeastern mountains.
/J. Cote`
Saturday through Thursday...model agreement exists as far as
maintaining an overall troughy flow regime over the region through
the extended period. There are significant differences in the
depiction of minor waves and disturbances transient through this
overall regime. The GFS is most consistent with the timing of the
only major feature/wave to impact the region...a beefy cold front
with plenty of precipitation potential way out on next Wednesday
or so.
So...for most of the forecast period a generally slightly cooler
than average regime featuring general small to medium chances for
afternoon and evening showers concentrated especially over the
mountains ringing the basin is called for. There will be no major
storm systems to impact the region until the aforementioned cold
front toward the middle of the new work week. Thus while the
holiday weekend will feature a threat of showers from time to
time...there does not appear to be any day that will be
particularly wet...or particularly dry either. The smallest chance
for showers will be in the Cascades lee zones and deep basin
with the highest chance in the mountains north and east of the
basin. The broad brush approach of daily small to moderate shower
chances may come across as somewhat weaselly...but is well justified
in this regime. /Fugazzi
&&
.AVIATION...
18Z TAFS: Low pressure and energy moving around it will push a swath
of precipitation across eastern WA and central ID panhandle this
morning. It is expected to weaken as it pushes north, but the still
approaching upper disturbance and daytime heating will help develop
other scattered showers this afternoon and evening, with a chance of
thunderstorms. Expect primarily VFR conditions but local MVFR or IFR
cigs are possible. The threat of showers will wane after
dark.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 57 42 63 44 67 47 / 80 40 20 10 10 10
Coeur d`Alene 57 42 63 42 66 43 / 60 50 20 10 20 20
Pullman 55 40 63 42 66 44 / 60 30 20 10 40 20
Lewiston 61 45 70 48 73 50 / 60 30 20 10 30 30
Colville 63 42 67 42 72 43 / 60 60 40 30 20 20
Sandpoint 58 41 62 39 66 41 / 60 60 30 20 30 30
Kellogg 54 42 60 43 64 46 / 70 60 40 30 30 30
Moses Lake 64 47 72 47 75 49 / 50 20 10 0 0 10
Wenatchee 63 49 68 48 72 51 / 40 20 10 0 10 10
Omak 63 42 68 42 73 44 / 40 40 20 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KSEW 241633
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
933 AM PDT FRI MAY 24 2013
.SYNOPSIS...AN AREA OF LOW PRESSURE WILL REMAIN OVER THE REGION
THROUGH THIS WEEKEND FOR CONTINUED SOMEWHAT UNSETTLED CONDITIONS.
HOWEVER...THE OVERALL TREND WILL BE TOWARD LESS SHOWERS...MORE
SUNSHINE...AND WARMER DAYTIME TEMPERATURES. MEMORIAL DAY MIGHT END
UP DRY FOR MUCH OF THE AREA.
&&
.SHORT TERM...
SOME AREAS IN THE NORTHERN PART OF THE CWA WERE SEEING SOME SUNSHINE
THIS MORNING. HOWEVER...WITH DAYTIME HEATING...LOOK FOR CUMULUS
CLOUDS TO BUBBLE UP WITHIN THESE CURRENTLY MOSTLY SUNNY AREAS.
THE 0900 UTC RUN OF THE SREF /SHORT RANGE ENSEMBLE FORECAST/
INDICATED INSTABILITY OVER THE NORTH CASCADES THIS AFTERNOON FOR A
SLIM RISK OF A TSTM. HOWEVER...THE STRONGEST LIFT THIS AFTERNOON
APPEARED TO BE OVER THE WESTERN PART OF THE FORECAST AREA...SO
WOULD NOT RULE OUT A FEW TSTMS OVER THIS AREA. WILL GO ON AHEAD
AND UPDATE THE FORECAST TO INCLUDE A MENTION OF AFTERNOON TSTMS
OVER THESE AREAS.
MEANWHILE...AN UPPER LOW WILL REMAIN OVER THE REGION THROUGH
SATURDAY MORNING. THE SHOWER THREAT WILL MAINLY BE DIURNAL IN
CHARACTER OR WITH THE GREATEST PROBABILITY AND COVERAGE DURING
THIS AFTERNOON AND EVENING. THE UPPER LOW WILL MOVE INTO EASTERN
WA SATURDAY AFTERNOON...WITH THE BEST THREAT OF SHOWERS BECOMING
CONFINED TO THE MOUNTAINS.
IT NOW APPEARS THAT SATURDAY NIGHT WILL BE MOSTLY DRY UNDER WEAK
CYCLONIC FLOW ALOFT. A WEAK UPPER TROF WILL REMAIN OVER THE REGION
ON SUNDAY FOR A CHANCE OF MAINLY AFTERNOON SHOWERS. IT LOOKS LIKE
THE BEST CHANCE OF SHOWERS WILL BE OVER THE SOUTHERN PART OF THE
FORECAST AREA.
.LONG TERM FROM THE PREV DISCUSSION...
COOL ONSHORE FLOW WILL PREVAIL THROUGH THE REST OF THE WEEK FOR
MOSTLY CLOUDY SKIES AND TEMPS NEAR NORMAL. MODELS SHOWED A LONG
WAVE TROUGH OVER THE PAC NW FOR ADDITIONAL SHOWERS ACROSS THE
REGION...AT LEAST THROUGH MIDWEEK. WEAK RIDGING MAY BRING DRIER
WEATHER BY THU OR FRI. 33
&&
.AVIATION...AN UPPER LEVEL TROUGH OVER WA WILL SLOWLY MIGRATE EWD
LATER TODAY AND TONIGHT. LIGHT VARIABLE FLOW BECOMING SWLY THIS
AFTERNOON. MOIST AND SLIGHTLY UNSTABLE. SCATTERED SHOWERS...WITH
BEST CHANCES FROM HQM SOUTH...DECREASING OVER ALL WESTERN WA BY
TONIGHT. LESS THAN A 10 PERCENT CHANCE OF ISOLATED THUNDERSTORMS
THIS AFTERNOON/EARLY EVENING.
KSEA...VARIABLE WIND TO 5 KT BECOMING S 5 TO 8 KT BY 16Z. MAINLY LOW
END VFR/HIGH END MVFR...DROPPING TO MVFR DURING SHOWERS. VFR CIGS
EXPECTED AFTER 18Z.
&&
.MARINE...LIGHTER GRADIENTS AND WINDS OVER THE WA WATERS TODAY AS
LOW PRESSURE MOVES INLAND. WEAK ONSHORE FLOW LATER TODAY INCREASES A
BIT TONIGHT THROUGH THE WEEKEND. INHERITED FORECAST PUT LOW END
SMALL CRAFT WINDS IN THE CENTRAL AND EASTERN STRAIT STARTING LATE
THIS AFTERNOON AND INTO THE OVERNIGHT HOURS...SO WILL SEND ADVISORY
WITH UPCOMING MORNING FORECAST.
THE NEXT ORGANIZED FRONT REACHES THE WATERS ON MONDAY WITH SMALL
CRAFT WINDS PROBABLE OVER THE COASTAL WATERS AND POSSIBLY SOME OF
THE INTERIOR WATERS.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO 2
AM PDT SATURDAY FOR THE CENTRAL AND EASTERN STRAIT OF JUAN DE
FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
FOR THE GRAPHICAL AFD...VISIT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
000
FXUS66 KPQR 241550
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
850 AM PDT FRI MAY 24 2013
.SYNOPSIS...THE UPPER LOW OVER WA FRI MORNING WILL WEAKEN THIS
WEEKEND AS IT LIFTS NE INTO ALBERTA. A FEW DISTURBANCES WILL
CONTINUE TO ROTATE AROUND THE LOW...KEEPING A THREAT OF SHOWERS IN
THROUGH THE WEEKEND WITH TEMPERATURES WARMING A BIT CLOSER TO
NORMAL. AN ACTIVE PATTERN WILL CONTINUE NEXT WEEK AS THE FLOW TURNS
WESTERLY...AND A SERIES OF WEAK DISTURBANCES COME IN OFF THE
PACIFIC.
&&
.SHORT TERM...WATER VAPOR PICTURES SHOWED THE UPPER LOW OVER CENTRAL
WA THIS MORNING...WITH THE MAIN VORTICITY LOBE LIFTING N THROUGH
IDAHO. A WEAK SURFACE LOW WAS SEEN JUST OFF THE COAST OF KAST...
LOCALLY ENHANCING THE LOW LEVEL ONSHORE FLOW OVER NW OREGON. SHOWERS
ON RADAR AND IN SURFACE OBSERVATIONS APPEAR TO BE FAVORING
OROGRAPHICALLY ENHANCED MOUNTAINS...ESP IN THE N. WILL KEEP SHOWERS
LIKELY TODAY IN THE N AND OVER THE MOUNTAINS...BUT GIVEN THE MAIN
SHORTWAVE LIFTING THE LOW NE...EXPECT THE HEAVY PRECIPITATION THREAT
IS GREATLY DIMINISHED TODAY.
REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...
THE UPPER LOW WILL SETTLE OVER THE CANADIAN ROCKIES FOR THE
WEEKEND...WITH A BROAD UPPER LEVEL TROUGHING PATTERN OVER THE PAC NW.
EXPECT OFF AND ON SHOWER ACTIVITY MUCH OF THE WEEKEND. THE BEST
CHANCE AT ANY ORGANIZED PRECIPITATION APPEARS TO BE SAT NIGHT INTO
EARLY SUN...AS THE MODELS ALL SHOW A SHORTWAVE OR WEAK CLOSED LOW
PUSHING INTO THE PAC NW. TEMPS SHOULD CONTINUE TO REBOUND...AS WE GET
MORE SUNBREAKS AND THE AIRMASS MODERATES. INLAND SITES SHOULD GET
INTO THE MID 60S ON BOTH SAT AND SUN.
ANOTHER MORE ORGANIZED SYSTEM IS BEING ADVERTISED ON MON. THERE IS
PLENTY OF MODEL UNCERTAINY WITH THIS SYSTEM...WITH SOME MODEL RUNS
STRETCHING THE UPPER LEVEL FORCING AND KEEPING THE BULK OF IT TO OUR
SOUTH. HOWEVER...IT APPEARS THAT WE WILL HAVE A DECENT SHOT AT
WIDESPREAD...ALBEIT LIGHT...PRECIPITATION. DECIDED TO GO WITH LIKELY
POPS LATER MON AS MOST MODELS ARE BRINGING PRECIP INTO OUR FCST AREA.
PYLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WESTERLY FLOW ALOFT LIKELY TO BE PERSIST THROUGH THE EARLY PART OF
THE WEEK. THIS WILL KEEP REGION UNDER A PERSISTENT CHANCE FOR RAIN AS
A SERIES OF SHORTWAVES MOVES THROUGH. THE WESTERLY FLOW OFF THE
PACIFIC WILL KEEP TEMPERATURES MODERATED...LIKELY A LITTLE BELOW
SEASONAL AVERAGES. MODELS TEND TO DIVERGE SOME LATE IN THE WEEK WITH
GFS AND CANADIAN CUTTING OFF AN UPPER LOW OFFSHORE. BOTTOM LINE
THOUGH IS FOR A CONTINUATION CHANCE OF RAIN.
&&
.AVIATION...WEAK LOW PRESSURE LINGERING OFFSHORE WILL MAINTAIN A
MOIST AIR MASS AND WEAK FLOW OVER THE AREA TODAY. THIS WILL ALLOW
SHOWERS AND LOCAL IFR/LOW MVFR CIGS TO REMAIN AT THE COAST AND
INLAND THROUGH 18Z. INCREASING S-SW FLOW IS EXPECTED TO BRING CIGS
ABOVE 2000 FT BY MIDDAY. HOWEVER OCCASIONAL SHOWERS WILL REDUCE CIGS
FROM TIME TO TIME...ESPECIALLY AT THE COAST WHERE CIGS LOOK TO
REMAIN IFR/LOW MVFR THROUGH THE DAY.
KPDX AND APPROACHES...WEAK FLOW AND MOIST AIR MASS WILL MAINTAIN
OCCASIONAL MVFR SHOWERS THROUGH 18Z. INCREASING S-SW FLOW SHOULD
RAISE CIGS ABOVE 2000 FT BY MIDDAY...WITH VFR IN SCATTERED SHOWERS
EXPECTED THIS AFTERNOON. WEAGLE/BURGESS
&&
.MARINE...NO UPDATES. SEAS HOVERING AROUND 8 TO 9 FT THIS MORNING
WILL BEGIN TO RELAX THIS AFTERNOON AS LOW PRES OFF ASTORIA MOVES
INLAND AND NW FETCH DIES DOWN. SEAS WILL CONTINUE TO SUBSIDE TO
AROUND 6 FT BY TONIGHT...AND REMAIN LESS THAN 6 FT THROUGH SUNDAY.
SOME GUSTS TO 20 KT REPORTED IN MAINLY THE SOUTHERN WATERS SHOULD
EASE TODAY/TONIGHT AS THE LOW PRES SYSTEM WEAKENS AND WEAK HIGH
PRES BUILDS OVER THE WATERS. A WEAK LOW PRES SYSTEM WILL MOVE
ACROSS THE OREGON WATERS LATE SAT/EARLY SUN...BUT WINDS SHOULD
GENERALLY STAY BELOW 25 KT. A MORE ORGANIZED SYSTEM IS POSSIBLE
FOR MON WHICH COULD PRODUCE A BRIEF COASTAL JET FOR GUSTS 30 TO 35
KT...BUT THIS DEPENDS ON THE TRACK. THERE IS STILL SOME
POSSIBILITY THIS SYSTEM COULD FOCUS MORE ON SRN OREGON AND NRN
CALIFORNIA THAN OUR WATERS.
MORNING EBBS REMAIN VERY STRONG DUE TO THE FULL MOON...SO EXPECT
ROUGH COLUMBIA RIVER BAR CONDITIONS THE NEXT COUPLE MORNINGS.
WEAGLE/BURGESS
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 AM
TO 8 AM PDT SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KPQR 241314 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED AVIATION SECTION
NATIONAL WEATHER SERVICE PORTLAND OR
615 AM PDT FRI MAY 24 2013
.SYNOPSIS...A COLD UPPER LEVEL CLOSED LOW IS CENTERED OVER WESTERN
WASHINGTON THIS MORNING. A SHORTWAVE ROTATING AROUND THE LOW BROUGHT
WIDESPREAD PRECIPITATION TO THE REGION YESTERDAY AND OVERNIGHT.
PRECIPITATION IS NOW TAPERING OFF...BUT EXPECT SHOWERS TO CONTINUE
MUCH OF THE DAY AS THE AIR MASS REMAINS RELATIVELY UNSTABLE WHILE THE
LOW SLOWLY MOVES TOWARD THE NORTHEAST. A BROAD AREA OF UPPER LEVEL
TROUGHING WILL REMAIN IN PLACE THIS WEEKEND TO KEEP A CHANCE OF
SHOWERS OVER THE AREA. THE MOST ORGANIZED PRECIPITATION OVER THE
WEEKEND WILL LIKELY ACCOMPANY A SHORTWAVE MOVING THROUGH LATE
SATURDAY INTO EARLY SUNDAY...BUT PRECIP SHOULD REMAIN LIGHT. A MORE
ORGANIZED OF SYSTEM COULD BRING A BETTER SHOT OF RAIN MONDAY.
GENERALLY UNSETTLED WEATHER SHOULD CONTINUE FOR MUCH OF NEXT
WEEK...WITH PERIODIC CHANCES FOR LIGHT PRECIPITATION.
&&
.SHORT TERM...THE CLOSED LOW PRESSURE SYSTEM SITTING OVER THE PAC NW
FOR MUCH OF THE WEEK IS NOW CENTERED OVER WESTERN WASHINGTON. A WAVE
OF EMBEDDED ENERGY ROTATING AROUND THE LOW BROUGHT ENHANCED
PRECIPITATION TO MOST OF THE REGION DURING THE DAY YESTERDAY AND
THROUGH THE OVERNIGHT HOURS. SEVERAL SITES PICKED UP AN ADDITIONAL 1
TO 2 INCHES OF RAINFALL OVER THE PAST 24 HRS...MAINLY IN THE NORTHERN
PORTIONS OF THE FCST AREA. IT APPEARS THAT SEVERAL MORE DAILY RECORD
RAINFALL RECORDS WERE SET YESTERDAY. HOWEVER...THE LATEST RADAR
IMAGERY SHOWS THAT PRECIP INTENSITY IS DECREASING SIGNIFICANTLY THIS
MORNING AS THE UPPER LEVEL FORCING VISIBLE ON WATER VAPOR SATELLITE
IS NOW MOSTLY THROUGH THE REGION. EXPECT THE HEAVIEST SHOWERS TO
CONTINUE OVER THE NEXT FEW HOURS OVER THE S WASHINGTON AND N OREGON
CASCADES AS THE LAST OF THE SHORTWAVE ENERGY PUSHES EAST. THE UPPER
LOW WILL BEGIN TO SLOWLY PUSH OFF TO THE NE TODAY. AS WARMER AIR
MOVES IN ALOFT...THE INSTABILITY WILL BE DECREASING. EXPECT JUST
SOME LIGHT LOW TOPPED SHOWERS ACROSS THE REGION TODAY...WITH A FEW
BREAKS IN THE CLOUDS POSSIBLE LATER IN THE DAY. TEMPS SHOULD REBOUND
A BIT...WITH THE INTERIOR LOWLANDS GETTING BACK INTO THE 60S.
THE UPPER LOW WILL SETTLE OVER THE CANADIAN ROCKIES FOR THE
WEEKEND...WITH A BROAD UPPER LEVEL TROUGHING PATTERN OVER THE PAC NW.
EXPECT OFF AND ON SHOWER ACTIVITY MUCH OF THE WEEKEND. THE BEST
CHANCE AT ANY ORGANIZED PRECIPITATION APPEARS TO BE SAT NIGHT INTO
EARLY SUN...AS THE MODELS ALL SHOW A SHORTWAVE OR WEAK CLOSED LOW
PUSHING INTO THE PAC NW. TEMPS SHOULD CONTINUE TO REBOUND...AS WE GET
MORE SUNBREAKS AND THE AIRMASS MODERATES. INLAND SITES SHOULD GET
INTO THE MID 60S ON BOTH SAT AND SUN.
ANOTHER MORE ORGANIZED SYSTEM IS BEING ADVERTISED ON MON. THERE IS
PLENTY OF MODEL UNCERTAINY WITH THIS SYSTEM...WITH SOME MODEL RUNS
STRETCHING THE UPPER LEVEL FORCING AND KEEPING THE BULK OF IT TO OUR
SOUTH. HOWEVER...IT APPEARS THAT WE WILL HAVE A DECENT SHOT AT
WIDESPREAD...ALBEIT LIGHT...PRECIPITATION. DECIDED TO GO WITH LIKELY
POPS LATER MON AS MOST MODELS ARE BRINGING PRECIP INTO OUR FCST AREA.
PYLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WESTERLY FLOW ALOFT LIKELY TO BE PERSIST THROUGH THE EARLY PART OF
THE WEEK. THIS WILL KEEP REGION UNDER A PERSISTENT CHANCE FOR RAIN AS
A SERIES OF SHORTWAVES MOVES THROUGH. THE WESTERLY FLOW OFF THE
PACIFIC WILL KEEP TEMPERATURES MODERATED...LIKELY A LITTLE BELOW
SEASONAL AVERAGES. MODELS TEND TO DIVERGE SOME LATE IN THE WEEK WITH
GFS AND CANADIAN CUTTING OFF AN UPPER LOW OFFSHORE. BOTTOM LINE
THOUGH IS FOR A CONTINUATION CHANCE OF RAIN.
&&
.AVIATION...UPDATE 615 AM...IT APPEARS ENOUGH SOUTHERLY FLOW AND
LOW-LEVEL MIXING HAS DEVELOPED TO REDUCE THE THREAT OF IFR/LOW MVFR
CIGS BOTH INLAND AND ALONG THE COAST. IN FACT MOST INLAND TERMINALS
ARE VFR AT THE MOMENT. THERE WILL STILL BE SOME AREAS MVFR THROUGH
MID MORNING...BECOMING LESS COMMON AS THE DAY GOES ON.
KPDX AND APPROACHES...UPDATE 615 AM...MAINLY VFR WITH AREAS OF MVFR
IN -RA/-DZ THIS MORNING. VFR WITH SCATTERED SHOWERS THIS AFTERNOON
AND EVENING. LIGHT TO MODERATE SOUTHERLY FLOW THRU THE DAY. WEAGLE
&&
.MARINE...SEAS HOVERING AROUND 10 FT IN THE OUTER WATERS AND 6 TO
8 FT IN THE INNER WATERS EARLY THIS MORNING. THE 10 FT SEAS SHOULD
BE SHORT-LIVED AS LOW PRES OFF ASTORIA WEAKENS AND NW FETCH DIES
DOWN. OPTED AGAINST SCA FOR SEAS AS THEY SHOULD BE BELOW 10 FT AT
ALL BUOYS BY SUNRISE. SEAS WILL CONTINUE TO SUBSIDE TODAY...
REMAINING AROUND 6 FT THROUGH THE WEEKEND.
SOME GUSTS TO 20 KT REPORTED IN MAINLY THE SOUTHERN WATERS SHOULD
EASE TODAY/TONIGHT AS THE LOW PRES SYSTEM WEAKENS AND WEAK HIGH
PRES BUILDS OVER THE WATERS. A WEAK LOW PRESSURE SYSTEM WILL MOVE
ACROSS THE OREGON WATERS LATE SAT/EARLY SUN...BUT WINDS SHOULD
GENERALLY STAY BELOW 25 KT. A MORE ORGANIZED SYSTEM IS POSSIBLE
FOR MON WHICH COULD PRODUCE A BRIEF COASTAL JET FOR GUSTS 30 TO
35 KT...BUT THIS DEPENDS ON THE TRACK. THERE IS STILL SOME
POSSIBILITY THIS SYSTEM COULD FOCUS MORE ON SRN OREGON AND NRN
CALIFORNIA THAN OUR WATERS.
MORNING EBBS REMAIN VERY STRONG DUE TO THE FULL MOON...SO EXPECT
ROUGH BAR CONDITIONS THE NEXT COUPLE MORNINGS.WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 8 AM
THIS MORNING AND AGAIN FROM 4 AM TO 8 AM SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 241203
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
503 AM PDT Fri May 24 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday, then a
subtle warming and drying trend is anticipated by Monday as the
upper-level low moves out of the area. The break will be
short lived as another cool, showery pattern returns around the
middle of next week.
&&
.DISCUSSION...
Today and tonight: An upper low and the shortwave pivoting around
it will provide a good chance of showers for the Inland Northwest,
especially this afternoon. The low and its associated shortwave
disturbance were tracking through Portland, Oregon this morning.
It was helping to generate the swath of precipitation along the
west and central WA/OR border and it was starting to reach toward
the Chelan-Grant-Adams-Garfield county borders.
Satellite/radar extrapolation and models are in good agreement in
tracking the low into the lower Columbia Basin later this morning,
before it pivots northeast through the Blue Mountains through
central Panhandle of ID this afternoon and early evening. This
will allow the swath of precipitation to continue it expansion
east and northeast. Coverage increases through the afternoon, with
the added threat of thunderstorms, working with the increased
convective instability with daytime heating. On average models
depict 100-200 J/kg of CAPE this afternoon and early evening,
before conditions begin to stabilize with the loss of daytime
heating.
The lack of strong lift and/or 0-6km shear suggests that any
thunderstorms that develop should not be too organized. The
exception lays around the Blue Mountains, Camas Prairie into the
Clearwaters where 30-60kts of shear are indicated. A few stronger
storms are possible here in the afternoon and evening. The
limiting factor may be cloud cover which could inhibit the
atmosphere from reaching it full convective potential.
After dark the threat of precipitation wanes, but doesn`t entirely
end and skies do not appear to clear completely as models string a
secondary weaker vorticity lobe in from the west. The primary
shower threat linger in the Cascades and northeastern mountains.
/J. Cote`
Saturday through Thursday...model agreement exists as far as
maintaining an overall troughy flow regime over the region through
the extended period. There are significant differences in the
depiction of minor waves and disturbances transient through this
overall regime. The GFS is most consistent with the timing of the
only major feature/wave to impact the region...a beefy cold front
with plenty of precipitation potential way out on next Wednesday
or so.
So...for most of the forecast period a generally slightly cooler
than average regime featuring general small to medium chances for
afternoon and evening showers concentrated especially over the
mountains ringing the basin is called for. There will be no major
storm systems to impact the region until the aforementioned cold
front toward the middle of the new work week. Thus while the
holiday weekend will feature a threat of showers from time to
time...there does not appear to be any day that will be
particularly wet...or particularly dry either. The smallest chance
for showers will be in the Cascades lee zones and deep basin
with the highest chance in the mountains north and east of the
basin. The broad brush approach of daily small to moderate shower
chances may come across as somewhat weaselly...but is well justified
in this regime. /Fugazzi
&&
.AVIATION...
12Z TAFS: Some patchy fog will impact the northeast valleys this
morning, mainly before 16Z. However it should remain largely away
from TAF sites. Low pressure and energy moving around it will help
push a swath of precipitation from Oregon into southern Washington
and the central Panhandle this morning. It is expected to weaken
as it pushes north, but the still approaching upper disturbance
and daytime heating will help develop other scattered showers this
afternoon and evening, with a chance of thunderstorms. Expect
primarily VFR conditions but local MVFR cigs are possible in
heavier showers. The threat of showers will wane after dark.
/J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 57 42 63 44 67 47 / 60 40 20 10 10 10
Coeur d`Alene 57 42 63 42 66 43 / 60 50 20 10 20 20
Pullman 55 40 63 42 66 44 / 60 30 20 10 40 20
Lewiston 61 45 70 48 73 50 / 60 30 20 10 30 30
Colville 63 42 67 42 72 43 / 60 60 40 30 20 20
Sandpoint 58 41 62 39 66 41 / 60 60 30 20 30 30
Kellogg 54 42 60 43 64 46 / 70 60 40 30 30 30
Moses Lake 64 47 72 47 75 49 / 50 20 10 0 0 10
Wenatchee 63 49 68 48 72 51 / 40 20 10 0 10 10
Omak 63 42 68 42 73 44 / 40 40 20 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KSEW 241021
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PDT THU MAY 23 2013
.SYNOPSIS...A SLOW MOVING COLD UPPER-LEVEL LOW WILL CONTINUE TO
PRODUCE SHOWERS ACROSS THE REGION TODAY. THE UPPER LOW WILL NOODLE
AROUND THE NORTHWEST INTO THE MEMORIAL DAY WEEKEND AS IT SLOWLY
FILLS AND WEAKENS. A WEAK FRONTAL SYSTEM WILL APPROACH THE REGION ON
MEMORIAL DAY BUT MAY SHIFT SOUTH INTO OREGON.
&&
.SHORT TERM...THE CLOSED UPPER LEVEL LOW THAT HAS BEEN SPINNING OVER
WESTERN WA WILL SHIFT INTO EASTERN WA TODAY. MODELS STILL GENERATE
ISOLATED TO SCATTERED SHOWERS ACROSS THE REGION...BUT PRECIP AMOUNTS
LOOK PRETTY LIGHT. POPS ARE HIGHEST OVER THE COAST AND SOUTH PART.
THE RADAR COMPOSITE SHOWS RAIN ALONG THE WA/OR BORDER THIS MORNING.
THE THREAT OF T-STORMS IS LOW AND MAINLY EAST OF THE CREST TODAY.
TEMPERATURES ARE STILL COOL ALOFT WITH 500 MB TEMPS IN THE -20S.
SURFACE TEMPS IN THE MID TO UPPER 50S LOOKS GOOD...WITH A FEW LOW
60S POSSIBLE.
THIS SYSTEM WILL ROTATE NORTH INTO B.C./ALBERTA OVER THE WEEKEND FOR
A MODEST WARM-UP...TEMPS ARE CLOSER TO NORMAL. THE MODELS STILL SHOW
A WEAK TROUGH OVER WESTERN WA FOR A CHANCE OF SHOWERS...BUT LOOKS
LIKE JUST ISOLATED COVERAGE. SNOW LEVELS WILL RISE TO 5000-6000 FT
IN THE MOUNTAINS.
MODELS ARE BACKING OFF ON THE NEXT INCOMING SYSTEM SLATED FOR
MEMORIAL DAY. THE ECMWF IS PUSHING THIS NEXT SYSTEM FARTHER SOUTH
WHICH WILL MAINLY AFFECT OREGON. BUT THE 00Z GFS AND NAM STILL SOME
MOISTURE REACHING THE AREA DURING THE DAY. SO WILL STICK WITH A
BLEND FOR NOW...CLOUDY WITH A CHANCE OF RAIN. BUT IF EVERYTHING
TRENDS TOWARD THE EURO THEN LOOK FOR A MAINLY DRY HOLIDAY.
.LONG TERM...COOL ONSHORE FLOW WILL PREVAIL THROUGH THE REST OF THE
WEEK FOR MOSTLY CLOUDY SKIES AND TEMPS NEAR NORMAL. MODELS SHOW A
LONG WAVE TROUGH OVER THE PAC NW FOR ADDITIONAL SHOWERS ACROSS THE
REGION...AT LEAST THROUGH MIDWEEK. WEAK RIDGING MAY BRING DRIER
WEATHER BY THU OR FRI. 33
&&
.AVIATION...AN UPPER LEVEL TROUGH OVER WA WILL SLOWLY MIGRATE EWD
LATER TODAY AND TONIGHT. LIGHT VARIABLE FLOW BECOMING SWLY THIS
AFTERNOON. MOIST AND SLIGHTLY UNSTABLE. SHOWERS...DECREASING LATER
TONIGHT. LESS THAN A 10 PERCENT CHANCE OF ISOLATED THUNDERSTORMS
THIS AFTERNOON/EARLY EVENING.
KSEA...VARIABLE OR N WIND TO 5 KT...BECOMING S 5 TO 8 KT AFTER 13Z.
A MIX OF LOW VFR...OR MVFR DURING SHOWERS. MAINLY VFR CIGS AFTER 18Z.
&&
.MARINE...LIGHTER GRADIENTS AND WINDS OVER THE WA WATERS TODAY AS
LOW PRESSURE OFF ASTORIA FILLS AND MOVES INLAND. WEAK ONSHORE FLOW
LATER TODAY INCREASES A BIT TONIGHT THROUGH THE WEEKEND. THERE WILL
BE A RISK FOR LOW END SMALL CRAFT WINDS IN THE CENTRAL/E STRAIT THE
NEXT COUPLE EVENINGS.
THE NEXT ORGANIZED FRONT REACHES THE WATERS ON MONDAY WITH SMALL
CRAFT WINDS PROBABLE OVER THE COASTAL WATERS AND POSSIBLY SOME OF
THE INTERIOR WATERS.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...NONE.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
000
FXUS66 KPQR 241001
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
300 AM PDT FRI MAY 24 2013
.SYNOPSIS...A COLD UPPER LEVEL CLOSED LOW IS CENTERED OVER WESTERN
WASHINGTON THIS MORNING. A SHORTWAVE ROTATING AROUND THE LOW BROUGHT
WIDESPREAD PRECIPITATION TO THE REGION YESTERDAY AND OVERNIGHT.
PRECIPITATION IS NOW TAPERING OFF...BUT EXPECT SHOWERS TO CONTINUE
MUCH OF THE DAY AS THE AIR MASS REMAINS RELATIVELY UNSTABLE WHILE THE
LOW SLOWLY MOVES TOWARD THE NORTHEAST. A BROAD AREA OF UPPER LEVEL
TROUGHING WILL REMAIN IN PLACE THIS WEEKEND TO KEEP A CHANCE OF
SHOWERS OVER THE AREA. THE MOST ORGANIZED PRECIPITATION OVER THE
WEEKEND WILL LIKELY ACCOMPANY A SHORTWAVE MOVING THROUGH LATE
SATURDAY INTO EARLY SUNDAY...BUT PRECIP SHOULD REMAIN LIGHT. A MORE
ORGANIZED OF SYSTEM COULD BRING A BETTER SHOT OF RAIN MONDAY.
GENERALLY UNSETTLED WEATHER SHOULD CONTINUE FOR MUCH OF NEXT
WEEK...WITH PERIODIC CHANCES FOR LIGHT PRECIPITATION.
&&
.SHORT TERM...THE CLOSED LOW PRESSURE SYSTEM SITTING OVER THE PAC NW
FOR MUCH OF THE WEEK IS NOW CENTERED OVER WESTERN WASHINGTON. A WAVE
OF EMBEDDED ENERGY ROTATING AROUND THE LOW BROUGHT ENHANCED
PRECIPITATION TO MOST OF THE REGION DURING THE DAY YESTERDAY AND
THROUGH THE OVERNIGHT HOURS. SEVERAL SITES PICKED UP AN ADDITIONAL 1
TO 2 INCHES OF RAINFALL OVER THE PAST 24 HRS...MAINLY IN THE NORTHERN
PORTIONS OF THE FCST AREA. IT APPEARS THAT SEVERAL MORE DAILY RECORD
RAINFALL RECORDS WERE SET YESTERDAY. HOWEVER...THE LATEST RADAR
IMAGERY SHOWS THAT PRECIP INTENSITY IS DECREASING SIGNIFICANTLY THIS
MORNING AS THE UPPER LEVEL FORCING VISIBLE ON WATER VAPOR SATELLITE
IS NOW MOSTLY THROUGH THE REGION. EXPECT THE HEAVIEST SHOWERS TO
CONTINUE OVER THE NEXT FEW HOURS OVER THE S WASHINGTON AND N OREGON
CASCADES AS THE LAST OF THE SHORTWAVE ENERGY PUSHES EAST. THE UPPER
LOW WILL BEGIN TO SLOWLY PUSH OFF TO THE NE TODAY. AS WARMER AIR
MOVES IN ALOFT...THE INSTABILITY WILL BE DECREASING. EXPECT JUST
SOME LIGHT LOW TOPPED SHOWERS ACROSS THE REGION TODAY...WITH A FEW
BREAKS IN THE CLOUDS POSSIBLE LATER IN THE DAY. TEMPS SHOULD REBOUND
A BIT...WITH THE INTERIOR LOWLANDS GETTING BACK INTO THE 60S.
THE UPPER LOW WILL SETTLE OVER THE CANADIAN ROCKIES FOR THE
WEEKEND...WITH A BROAD UPPER LEVEL TROUGHING PATTERN OVER THE PAC NW.
EXPECT OFF AND ON SHOWER ACTIVITY MUCH OF THE WEEKEND. THE BEST
CHANCE AT ANY ORGANIZED PRECIPITATION APPEARS TO BE SAT NIGHT INTO
EARLY SUN...AS THE MODELS ALL SHOW A SHORTWAVE OR WEAK CLOSED LOW
PUSHING INTO THE PAC NW. TEMPS SHOULD CONTINUE TO REBOUND...AS WE GET
MORE SUNBREAKS AND THE AIRMASS MODERATES. INLAND SITES SHOULD GET
INTO THE MID 60S ON BOTH SAT AND SUN.
ANOTHER MORE ORGANIZED SYSTEM IS BEING ADVERTISED ON MON. THERE IS
PLENTY OF MODEL UNCERTAINY WITH THIS SYSTEM...WITH SOME MODEL RUNS
STRETCHING THE UPPER LEVEL FORCING AND KEEPING THE BULK OF IT TO OUR
SOUTH. HOWEVER...IT APPEARS THAT WE WILL HAVE A DECENT SHOT AT
WIDESPREAD...ALBEIT LIGHT...PRECIPITATION. DECIDED TO GO WITH LIKELY
POPS LATER MON AS MOST MODELS ARE BRINGING PRECIP INTO OUR FCST AREA.
PYLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WESTERLY FLOW ALOFT LIKELY TO BE PERSIST THROUGH THE EARLY PART OF
THE WEEK. THIS WILL KEEP REGION UNDER A PERSISTENT CHANCE FOR RAIN AS
A SERIES OF SHORTWAVES MOVES THROUGH. THE WESTERLY FLOW OFF THE
PACIFIC WILL KEEP TEMPERATURES MODERATED...LIKELY A LITTLE BELOW
SEASONAL AVERAGES. MODELS TEND TO DIVERGE SOME LATE IN THE WEEK WITH
GFS AND CANADIAN CUTTING OFF AN UPPER LOW OFFSHORE. BOTTOM LINE
THOUGH IS FOR A CONTINUATION CHANCE OF RAIN.
&&
.AVIATION...WEAK LOW PRESSURE LINGERING OFFSHORE FROM ASTORIA
CONTINUES TO SPREAD AREAS OF -RA/-DZ ONSHORE. HOWEVER IT APPEARS
THE HEAVIEST AND STEADIEST PRECIPITATION HAS SHIFTED EAST INTO THE
CASCADES. MOIST AIR MASS AND WEAK FLOW WILL PROBABLY CAUSE SOME
IFR/LOW MVFR TO DEVELOP COAST AND INLAND BY SUNRISE. HOWEVER
INCREASING S-SW FLOW SHOULD PUSH CIGS ABOVE 2000 FT BY MIDDAY.
THIS AFTERNOON AND EVENING WILL BE MAINLY VFR WITH SOME MVFR IN
SCATTERED SHOWERS.
KPDX AND APPROACHES...WEAK FLOW AND MOIST AIR MASS WILL LIKELY
RESULT IN CIGS BELOW 1500 FT THROUGH 16Z...WITH SOME AREAS OF IFR
EMBEDDED WITHIN. AREAS -RA/-DZ CONTINUING THROUGH THIS MORNING.
INCREASING S-SW FLOW SHOULD RAISE CIGS ABOVE 2000 FT BY MIDDAY
WITH VFR BUT SCATTERED SHOWERS THIS AFTERNOON.WEAGLE
&&
.MARINE...SEAS HOVERING AROUND 10 FT IN THE OUTER WATERS AND 6 TO
8 FT IN THE INNER WATERS EARLY THIS MORNING. THE 10 FT SEAS SHOULD
BE SHORT-LIVED AS LOW PRES OFF ASTORIA WEAKENS AND NW FETCH DIES
DOWN. OPTED AGAINST SCA FOR SEAS AS THEY SHOULD BE BELOW 10 FT AT
ALL BUOYS BY SUNRISE. SEAS WILL CONTINUE TO SUBSIDE TODAY...
REMAINING AROUND 6 FT THROUGH THE WEEKEND.
SOME GUSTS TO 20 KT REPORTED IN MAINLY THE SOUTHERN WATERS SHOULD
EASE TODAY/TONIGHT AS THE LOW PRES SYSTEM WEAKENS AND WEAK HIGH
PRES BUILDS OVER THE WATERS. A WEAK LOW PRESSURE SYSTEM WILL MOVE
ACROSS THE OREGON WATERS LATE SAT/EARLY SUN...BUT WINDS SHOULD
GENERALLY STAY BELOW 25 KT. A MORE ORGANIZED SYSTEM IS POSSIBLE
FOR MON WHICH COULD PRODUCE A BRIEF COASTAL JET FOR GUSTS 30 TO
35 KT...BUT THIS DEPENDS ON THE TRACK. THERE IS STILL SOME
POSSIBILITY THIS SYSTEM COULD FOCUS MORE ON SRN OREGON AND NRN
CALIFORNIA THAN OUR WATERS.
MORNING EBBS REMAIN VERY STRONG DUE TO THE FULL MOON...SO EXPECT
ROUGH BAR CONDITIONS THE NEXT COUPLE MORNINGS.WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 8 AM
THIS MORNING AND AGAIN FROM 4 AM TO 8 AM SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 240920
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
220 AM PDT Fri May 24 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday, then a
subtle warming and drying trend is anticipated by Monday as the
upper-level low moves out of the area. The break will be
short lived as another cool, showery pattern returns around the
middle of next week.
&&
.DISCUSSION...
Today and tonight: An upper low and the shortwave pivoting around
it will provide a good chance of showers for the Inland Northwest,
especially this afternoon. The low and its associated shortwave
disturbance were tracking through Portland, Oregon this morning.
It was helping to generate the swath of precipitation along the
west and central WA/OR border and it was starting to reach toward
the Chelan-Grant-Adams-Garfield county borders.
Satellite/radar extrapolation and models are in good agreement in
tracking the low into the lower Columbia Basin later this morning,
before it pivots northeast through the Blue Mountains through
central Panhandle of ID this afternoon and early evening. This
will allow the swath of precipitation to continue it expansion
east and northeast. Coverage increases through the afternoon, with
the added threat of thunderstorms, working with the increased
convective instability with daytime heating. On average models
depict 100-200 J/kg of CAPE this afternoon and early evening,
before conditions begin to stabilize with the loss of daytime
heating.
The lack of strong lift and/or 0-6km shear suggests that any
thunderstorms that develop should not be too organized. The
exception lays around the Blue Mountains, Camas Prairie into the
Clearwaters where 30-60kts of shear are indicated. A few stronger
storms are possible here in the afternoon and evening. The
limiting factor may be cloud cover which could inhibit the
atmosphere from reaching it full convective potential.
After dark the threat of precipitation wanes, but doesn`t entirely
end and skies do not appear to clear completely as models string a
secondary weaker vorticity lobe in from the west. The primary
shower threat linger in the Cascades and northeastern mountains.
/J. Cote`
Saturday through Thursday...model agreement exists as far as
maintaining an overall troughy flow regime over the region through
the extended period. There are significant differences in the
depiction of minor waves and disturbances transient through this
overall regime. The GFS is most consistent with the timing of the
only major feature/wave to impact the region...a beefy cold front
with plenty of precipitation potential way out on next Wednesday
or so.
So...for most of the forecast period a generally slightly cooler
than average regime featuring general small to medium chances for
afternoon and evening showers concentrated especially over the
mountains ringing the basin is called for. There will be no major
storm systems to impact the region until the aforementioned cold
front toward the middle of the new work week. Thus while the
holiday weekend will feature a threat of showers from time to
time...there does not appear to be any day that will be
particularly wet...or particularly dry either. The smallest chance
for showers will be in the Cascades lee zones and deep basin
with the highest chance in the mountains north and east of the
basin. The broad brush approach of daily small to moderate shower
chances may come across as somewhat weaselly...but is well justified
in this regime. /Fugazzi
&&
.AVIATION...
06Z TAFS: Clear skies across much of the northern areas is
expected to result in some fog developing late tonight into
earlier tomorrow morning. Fog is expected to develop at the KSFF
TAF site around 12Z with decreasing vis into MVFR category expected.
The main low pressure system is expected to slide eastward through
the morning with increasing mid level cloud cover from the west.
Light rain will develop along the leading edge of the system with
convective showers expected to develop across much of the region by
Friday afternoon. Isolated thunderstorms will be possible across
the region in the afternoon. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 57 42 63 44 67 47 / 60 40 20 10 10 10
Coeur d`Alene 57 42 63 42 66 43 / 60 50 20 10 20 20
Pullman 55 40 63 42 66 44 / 60 30 20 10 40 20
Lewiston 61 45 70 48 73 50 / 60 30 20 10 30 30
Colville 63 42 67 42 72 43 / 60 60 40 30 20 20
Sandpoint 58 41 62 39 66 41 / 60 60 30 20 30 30
Kellogg 54 42 60 43 64 46 / 70 60 40 30 30 30
Moses Lake 64 47 72 47 75 49 / 50 20 10 0 0 10
Wenatchee 63 49 68 48 72 51 / 40 20 10 0 10 10
Omak 63 42 68 42 73 44 / 40 40 20 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 240558
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1058 PM PDT Thu May 23 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday then a
subtle warming and drying trend is anticipated by Monday as the
persistent upper-level low moves out of the area. The break will
be short-lived as another cool and showery pattern returns around
the middle of next week.
&&
.DISCUSSION...
A quick Update to increase fog across the northern mountain
valleys. Clear skies over these areas have resulted in rapid
decreases in temps with dew point depressions nearing zero. Fog is
expected to redevelop tonight in many of the same areas as last
night. Low temperatures should remain just above freezing for most
locations; thus, the frost that was added to the forecast earlier
was converted to fog. /SVH
&&
.AVIATION...
00Z TAFS: Clear skies across much of the northern areas is
expected to result in some fog developing late tonight into
earlier tomorrow morning. Fog is expected to develop at the KSFF
TAF site around 12Z with decreasing vis into MVFR category expected.
The main low pressure system is expected to slide eastward through
the morning with increasing mid level cloud cover from the west.
Light rain will develop along the leading edge of the system with
convective showers expected to develop across much of the region by
Friday afternoon. Isolated thunderstorms will be possible across
the region in the afternoon. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 56 42 63 44 67 / 0 60 30 20 10 10
Coeur d`Alene 38 56 41 63 42 67 / 0 60 40 20 10 20
Pullman 37 55 40 63 41 66 / 10 60 30 20 10 40
Lewiston 43 61 45 70 48 73 / 10 50 30 20 10 30
Colville 36 62 42 67 43 73 / 0 50 50 40 30 20
Sandpoint 36 58 40 62 40 66 / 0 70 50 30 20 30
Kellogg 39 54 41 60 43 64 / 0 70 60 40 30 30
Moses Lake 42 64 46 72 47 75 / 10 40 20 10 0 0
Wenatchee 43 63 48 69 48 72 / 20 40 20 10 0 10
Omak 36 64 42 68 42 73 / 10 40 30 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KSEW 240434
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
934 PM PDT THU MAY 23 2013
.SYNOPSIS...A SLOW MOVING COLD UPPER-LEVEL LOW WILL CONTINUE TO
PRODUCE SHOWERS ACROSS THE REGION TONIGHT. THE UPPER LOW WILL WOBBLE
AROUND THE PACIFIC NORTHWEST INTO THE MEMORIAL DAY WEEKEND AS IT
SLOWLY FILLS AND WEAKENS. THE COOL AIR MASS WILL GRADUALLY MODERATE
INTO THE WEEKEND AND SHOWERS WILL GRADUALLY DIMINISH STARTING
TONIGHT.
&&
.SHORT TERM...A CLOSED UPPER LEVEL LOW WILL CONTINUE TO SLOWLY SPIN
OVER THE REGION TONIGHT FOR ADDITIONAL LIGHT PRECIP ACROSS THE
AREA. THERE WERE A FEW THUNDERSTORMS OVER WHATCOM AND SKAGIT
COUNTIES AROUND 23Z...BUT NO ACTIVITY SINCE. SHOWERS ARE ISOLATED
OVER THE NORTHWEST INTERIOR WITH LIGHT STRATIFORM PRECIP FROM THE
COAST TO PUGET SOUND. THE CURRENT FORECAST LOOKS GOOD WITH NO
PLANNED UPDATES TONIGHT.
THE UPPER LOW CENTER WILL SHIFT INTO EASTERN WA ON FRIDAY...WITH
SCATTERED SHOWERS ACROSS WESTERN WA. TEMPERATURES ARE STILL PRETTY
COOL ALOFT WITH 500 MB TEMPS IN THE -20S. SURFACE TEMPS IN THE MID
TO UPPER 50S LOOK GOOD...WITH A FEW LOW 60S POSSIBLE.
THIS SYSTEM WILL ROTATE NORTH INTO B.C./ALBERTA OVER THE WEEKEND FOR
A MODEST WARM-UP...TEMPS ARE CLOSER TO NORMAL. THE MODELS STILL SHOW
A WEAK TROUGH OVER WESTERN WA FOR A CHANCE OF SHOWERS BUT LOOKS LIKE
JUST ISOLATED COVERAGE. SNOW LEVELS WILL RISE TO 5000-6000 FT IN THE
MOUNTAINS. 33
.LONG TERM...PREVIOUS DISCUSSION...THE GFS CONTINUES TO BRING A WEAK
SYSTEM INLAND AROUND MONDAY OR TUESDAY. THE EURO IS STARTING TO COME
AROUND TO THIS IDEA EXCEPT THAT IT SENDS THE SYSTEM SOUTH INTO
OREGON AND CALIFORNIA. HAVE RAIN LIKELY FOR A FEW PERIODS IN THE
EXTENDED BUT AM NOT CONFIDENT IN THE DETAILS. BACK TO SCATTERED
SHOWERS STARTING ABOUT WEDNESDAY. TEMPERATURES ARE LIKELY TO BE NEAR
NORMAL. BURKE
&&
.AVIATION...UPPER LEVEL LOW PRESSURE CENTERED OVER WRN WA TONIGHT
WILL VERY GRADUALLY SHIFT EWD FRIDAY. LIGHT VARIABLE FLOW ALOFT
TONIGHT...BECOMING LIGHT SWLY FLOW ON FRIDAY. MOIST AT ALL LEVELS
AND SOMEWHAT UNSTABLE. SHOWERS...DECREASING LATER TONIGHT AND
FRIDAY. THE RISK OF AN ISOLATED THUNDERSTORM IS LESS THAN 10
PERCENT. MOSTLY VFR CIGS EXCEPT MVFR UNDER RAIN BANDS OR SHOWERS.
KSEA...NW WIND 3-6 KT...BECOMING S 5-8 KT AFTER 5 AM PDT (12Z). DTM
&&
.MARINE...A 1014 MB LOW CENTER STALLED JUST W OF ASTORIA WILL WEAKEN
AND MOVE INLAND FRIDAY MORNING. SOUTHEAST/EASTERLY GRADIENT IS
STRONG ENOUGH TO SUPPORT LOW-END SMALL CRAFT WINDS IN ADMIRALTY
INLET/AND THE CENTRAL/E STRAIT OF JUAN DE FUCA THROUGH MIDNIGHT
BEFORE EASING. SE WINDS OVER THE SRN PORTION OF THE WA COASTAL
WATERS MAY ALSO REACH SMALL CRAFT CRITERIA THIS EVENING. WINDS WILL
EASE FURTHER OVERNIGHT.
A FRONT WILL APPROACH THE PACIFIC NORTHWEST FROM THE WEST MONDAY AND
WEAKEN AS IT MOVES INLAND MONDAY NIGHT. AT THIS POINT IT LOOKS LIKE
IT WILL PRODUCE SMALL CRAFT ADVISORY WINDS OVER THE COASTAL WATERS.
WEAK ONSHORE FLOW WILL DEVELOP AGAIN TUESDAY. DTM/MCDONNAL
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY CENTRAL/EAST STRAIT OF JUAN DE
FUCA...ADMIRALTY INLET...AND THE SOUTHERN HALF OF THE WA
COASTAL WATERS THROUGH MIDNIGHT.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
000
FXUS66 KPQR 240358
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
858 PM PDT THU MAY 23 2013
.SYNOPSIS...AN UNSEASONABLY COLD UPPER LEVEL WAS CENTERED ALONG THE
WASHINGTON COAST THIS EVENING AND WILL MOVE INLAND AND EASTWARD
TONIGHT AND FRIDAY. THE LAST MAIN BATCH OF WRAP AROUND MOISTURE WILL
MOVE THROUGH SOUTHWEST WASHINGTON AND NORTHWEST OREGON TONIGHT AND
EARLY FRIDAY. ONE MORE SHOT WAVE ON THE BACK OR WEST SIDE OF THE LOW
WILL SWING THROUGH OUR FORECAST AREA LATER FRIDAY AND FRIDAY NIGHT TO
CONTINUE SOME SHOWERS. SOME LOWER PRESSURE WILL REMAIN OVER THE AREA
THIS WEEKEND TO KEEP A CHANCE OF SHOWERS OVER THE AREA. A COUPLE OF
SYSTEMS ARE EXPECTED NEXT WEEK FOR INCREASED PRECIPITATION CHANCES.
&&
.SHORT TERM...THE UPPER LOW THAT HAS BEEN PLAGUING THE PACIFIC
NORTHWEST THE LAST FEW DAYS WITH COPIOUS PRECIPITATION WAS CENTERED
ALONG THE CENTRAL WASHINGTON COAST THIS EVENING. THE LAST BIG SLUG OF
MOISTURE WRAPPING AROUND THE LOW WAS MOVING SLOWLY EASTWARD THROUGH
SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS EVENING ASSOCIATED
WITH A SOLID LOOKING VORT LOBE OR MAX. THE MODELS SHOW THIS SLUG OF
MOISTURE WILL MOVE EAST OF THE CASCADES BY SUNRISE ON FRIDAY. QPF AS
IT MOVES THROUGH WILL BE PRETTY SUBSTANTIAL AGAIN. ASTORIA HAD 1.15
INCHES IN THE 6 HOURS ENDING AT 5 PM...WITH ANOTHER .69 INCHES SINCE
5 PM THOUGH IT IS STARTING TO SLOW DOWN. THUS LOOK FOR HALF TO ONE
INCH AMOUNTS IN THE MOUNTAINS AS THIS FEATURE MOVES THROUGH...WITH A
HALF INCH OR SO IN THE VALLEYS.
THE MAIN LOW CIRCULATION WILL MOVE EAST FRIDAY AS THIS LAST STRONGER
VORT LOBE MOVES EAST. HOWEVER...THERE IS ONE MORE SHORT WAVE THAT
WILL SWING AROUND ON THE BACK SIDE OF THE LOW AND ACROSS THE NORTHERN
PART OF OUR FORECAST AREA LATE FRIDAY AND FRIDAY NIGHT FOR A SOME
MORE SHOWERS...BUT LESS QPF THAN THE LAST FEW NIGHTS.
THERE IS STILL SOME CYCLONIC FLOW AND ENERGY AROUND OUR AREA THIS
WEEKEND...WITH A DECENT SHORT WAVE DIGGING SOUTH SATURDAY NIGHT AND
SUNDAY TOWARD SOUTHERN OREGON. SOME MODEL DETAILS STILL ARE NOT IN
VERY GOOD AGREEMENT...BUT THE BOTTOM LINE THERE IS AT LEAST A CHANCE
OF SHOWERS MUCH OF THE WEEKEND.
LOOKS LIKE WE MAY HAVE 2 MORE RECORD LOW MAXIMUM TEMPS TODAY AT
ASTORIA AND HILLSBORO. THERE WILL LIKELY BE SEVERAL RECORD RAINFALL
AMOUNTS AS WELL. TEMPS TODAY WERE A COUPLE OF DEGREES HIGHER THAN
THOSE THURSDAY AS EXPECTED...AND SHOULD MAKE UPPER 50S TO NEAR 60
FRIDAY AS THE AIR MASS WARMS SLIGHTLY...WITH LOWER TO MID 60S
POSSIBLE SATURDAY. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WESTERLY FLOW ALOFT LIKELY TO BE PERSIST THROUGH THE EARLY PART OF
THE WEEK. THIS WILL KEEP REGION UNDER A PERSISTENT CHANCE FOR RAIN AS
A SERIES OF SHORTWAVES MOVES THROUGH. THE WESTERLY FLOW OFF THE
PACIFIC WILL KEEP TEMPERATURES MODERATED...LIKELY A LITTLE BELOW
SEASONAL AVERAGES. MODELS TEND TO DIVERGE SOME LATE IN THE WEEK WITH
GFS AND CANADIAN CUTTING OFF AN UPPER LOW OFFSHORE. BOTTOM LINE
THOUGH IS FOR A CONTINUATION CHANCE OF RAIN.
&&
.AVIATION...ANOTHER ROUND OF LIGHT TO MODERATE RAIN IMPACTING THE
COAST WITH A MIX OF VFR AND MVFR CIGS/VIS. RAIN WILL EASE LATE
TONIGHT BUT MVFR CONDITIONS LIKELY HANGING AROUND THROUGH MIDDAY FRI.
FOR INLAND AREAS...MAINLY VFR EXPECTED TONIGHT WITH AREAS OF MVFR
OCCURRING MAINLY NORTH OF KSLE AS THE RAIN MOVING INLAND. OVERALL
FLIGHT CONDITIONS IMPROVING AS RAIN DECREASES AND TURNS TO SCATTERED
SHOWERS LATE FRI MORNING. CASCADES FREQUENTLY OBSCURED THROUGH
TONIGHT.
KPDX AND APPROACHES...NEXT BATCH OF RAIN SWINGING INLAND THIS EVENING
SO EXPECT MVFR CIGS AND/OR VIS AT TIME THROUGH ABOUT 12Z. CIGS
IMPROVE A BIT EARLY FRI WITH HIGHER MVFR TO LOW VFR EXPECTED.
&&
.MARINE...ALL BUOYS NOW REPORTING SEAS BETWEEN 7 AND 9 FT THIS
EVENING. SEAS WILL CONTINUE TO SUBSIDE SLOWLY OVERNIGHT AND FRI AND
REMAIN AROUND 6 FT THROUGH THE WEEKEND.
A WEAK LOW PRES CENTER OVER THE NORTH COASTAL WATERS WITH WINDS BELOW
10 KT BUT A LITTLE STRONGER PRES GRADIENT OFFSHORE AND TO THE SOUTH
WILL KEEP WINDS IN THAT AREA A LITTLE HIGHER TONIGHT. WINDS RELAX FRI
MORNING AS THE LOW PRES DISSIPATES AND HIGH PRES BUILDS FROM THE
SOUTHWEST LATER FRI. THE NEXT SYSTEM COULD INCREASE WINDS/SEAS LATER
SUN OR MON...BUT STILL UNCERTAINTY ON THE TRACK AND STRENGTH OF THIS
SYSTEM. NO CHANGES FOR NOW...AS LOOKS TO BE DECENT POTENTIAL FOR 20
TO 25 KT SOUTHERLY WINDS WITH THAT FRONT. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 3 AM
TO 8 AM PDT FRIDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 240210
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
710 PM PDT Thu May 23 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday then a
subtle warming and drying trend is anticipated by Monday as the
persistent upper-level low moves out of the area. The break will
be short-lived as another cool and showery pattern returns around
the middle of next week.
&&
.DISCUSSION...
Update: A little bit of a tough call for the low temperatures
tonight across the mountain valley locations. There are a few
different factors working with and against each other for freezing
temperatures across the mountain valleys across the north. I am
expecting mostly clear skies tonight mainly across the Okanogan
Valley/Highlands eastward over to the Northeast Mtns. There will
be some high level cloud cover moving northward across the ID
Panhandle tonight. This cloud cover can be seen on satellite
imagery moving across the Clearwaters early this evening. This
cloud cover will mainly track across western Montana, but places
like St. Maries, Coeur d`Alene, Sandpoint and Bonners Ferry will
be along the western fringe of this high level cloud shield. This
will help to limit a bit how much radiational cooling these areas
will see. Surface dew point temperatures will be a couple degrees
colder tonight compared to last night and surface temperatures
will be starting out around 10 degrees warmer across these
locations. Although we will be a bit drier, with temperatures
starting out significantly warmer tonight, we may have a hard time
reaching the freezing mark. The best chances for some freezing
temperatures tonight will be where skies will remain relatively
cloud free, including Republic, Colville, Metaline Falls, Chewelah
and Deer Park. I don`t think freezing temperatures will be
widespread enough for a warning, but typical cold pockets may
reach freezing for an hour or two right around sunrise. I also
added some patchy frost across these locations as the drier air
tonight should result in less fog formation compared to last
night. However, I can not rule out a little bit of fog in the
northern valleys considering how moist we were last night,
especially where any little showers formed late this afternoon
into the early evening hours. /SVH
&&
.AVIATION...
00Z TAFS: Afternoon showers are expected until sunset over mainly
the higher terrain; although, we will see some isolated showers
develop over the basin as well. The main threat for thunderstorms
will be over the NE Blue Mtns through 03Z and may hold together long
enough to impact KLWS. Skies are expected to clear out over much of
the northern half of the area tonight and we may see some fog
develop across these mountain valleys. Fog coverage will likely be
less compared to early this morning as the boundary layer will be
slightly drier tonight; however, some fog could form in the vicinity
of KSFF, but confidence is low at this time and was not mentioned in
the TAF. The main low generating these showers will slowly drift
into eastern WA by Friday morning with showers expected to develop
from south to north through Friday over the region. Isolated
thunderstorms will be possible across the region Friday afternoon,
but confidence is too low at this time to include mention of
thunder at any TAF site at this time. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 56 42 63 44 67 / 10 60 30 20 10 10
Coeur d`Alene 38 56 41 63 42 67 / 10 60 40 20 20 20
Pullman 37 55 40 63 41 66 / 10 60 30 20 20 20
Lewiston 43 61 45 70 48 73 / 20 50 30 20 20 30
Colville 36 62 42 67 43 73 / 20 50 50 40 30 20
Sandpoint 36 58 40 62 40 66 / 0 70 50 30 30 30
Kellogg 39 54 41 60 43 64 / 10 70 60 40 30 20
Moses Lake 42 64 46 72 47 75 / 20 40 20 10 10 0
Wenatchee 43 63 48 69 48 72 / 30 40 20 10 10 0
Omak 36 64 42 68 42 73 / 20 40 30 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 232356
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
457 PM PDT Thu May 23 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday then a
subtle warming and drying trend is anticipated by Monday as the
persistent upper-level low moves out of the area. The break will
be short-lived as another cool and showery pattern returns around
the middle of next week.
&&
.DISCUSSION...
Tonight and Friday...A large closed low near the central
Washington coast this afternoon will move southeast towards
Portland overnight. As it does so most of the rain associated with
this low will remain south and west of the area. However...a cold
pool aloft associated with this large low will result in an
unstable atmosphere through early this evening promoting isolated
showers except for a bit more coverage near the Cascades given
closer proximity to low. LAPS data this afternoon also shows
surface based CAPE values of 200-400 J/KG near the Cascades, and
over the Blue Mountains where a few lightning strikes are
possible. Once daytime heating is lost, these showers will fall
apart with dry conditions expected for the late evening and
overnight hours. Another cool night is in store with localized
freezing temperatures possible in the Okanogan Highlands and
Northeast Washington valleys where skies are expected to clear
more significantly overnight. On Friday the low will move east
across south central Washington in the morning...and then rotate
northeast towards the Spokane and Palouse areas in the early
afternoon...and finally into the Central Panhandle Mountains mid
to late afternoon. This is the solution the ECMWF and NAM models
show and is preferred...compared to the slightly more southerly
GFS track. This will promote a cool and showery day over the
Inland Northwest with the greatest coverage of showers focused
along the low track and in the mountains. There will be a slight
chance of thunderstorms Friday afternoon as well over the area
with forecast CAPES of 200-500 J/KG over the region. JW
Friday night through Sunday night: The upper-level low that
has been parked over the region the last few days will continue
to have an influence on the weather but does show signs of
filling/warming. This will translate into less widespread and
weaker shower activity each afternoon; especially across the
Columbia Basin and into the latter half of the holiday weekend.
There are a few weak waves embedded within the parent low which
will keep a slight chance for PoPs during the overnight periods at
times...but in general, most shower activity will be middle to
late afternoon and focused over the northern and eastern
mountains. The best chance for thunderstorms will be Friday
evening...with very small chances Saturday...then a slight threat
near the Blues and Camas Prairie Sunday. Temperatures over the
period will be slowly climbing back near seasonal readings or
upper 60`s to mid 70`s. /sb
Monday through Thursday...Some significant shortwave features of
note to lock in on and add more detail courtesy of general
longwave trof lingering and influencing a good portion of the
Western United States through this time interval. Significant
features of note include what could be described as a deformation
zone of sorts sandwiched between the upper right corner of a large
low embedded in the longwave trof that gets squashed against
higher pressure influencing Central Canada that the GFS in
particular has lingering on and influencing Wednesday and Thursday
with continued wet weather. Otherwise Monday into very early
Tuesday morning appear to be the interval potentially least cluttered
with shortwave triggers so it remains assigned with the lowest
pops. Tuesday afternoon/evening are hinted at as having negatively
tilted trof passing as a kicker thus the pops and precipitation
amounts show an increase. Due to this longwave trof pattern
persisting forecast temperatures will generally remain on the cool
side of what would be considered normal for this time of year
through this time interval. /Pelatti
&&
.AVIATION...
00Z TAFS: Afternoon showers are expected until sunset over mainly
the higher terrain; although, we will see some isolated showers
develop over the basin as well. The main threat for thunderstorms
will be over the NE Blue Mtns through 03Z and may hold together long
enough to impact KLWS. Skies are expected to clear out over much of
the northern half of the area tonight and we may see some fog
develop across these mountain valleys. Fog coverage will likely be
less compared to early this morning as the boundary layer will be
slightly drier tonight; however, some fog could form in the vicinity
of KSFF, but confidence is low at this time and was not mentioned in
the TAF. The main low generating these showers will slowly drift
into eastern WA by Friday morning with showers expected to develop
from south to north through Friday over the region. Isolated
thunderstorms will be possible across the region Friday afternoon,
but confidence is too low at this time to include mention of
thunder at any TAF site at this time. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 56 42 63 44 67 / 20 60 30 20 10 10
Coeur d`Alene 38 56 41 63 42 67 / 10 60 40 20 20 20
Pullman 37 55 40 63 41 66 / 20 60 30 20 20 20
Lewiston 43 61 45 70 48 73 / 20 50 30 20 20 30
Colville 36 62 42 67 43 73 / 20 50 50 40 30 20
Sandpoint 36 58 40 62 40 66 / 10 70 50 30 30 30
Kellogg 39 54 41 60 43 64 / 10 70 60 40 30 20
Moses Lake 42 64 46 72 47 75 / 20 40 20 10 10 0
Wenatchee 43 63 48 69 48 72 / 30 40 20 10 10 0
Omak 36 64 42 68 42 73 / 20 40 30 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KSEW 232218
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
315 PM PDT THU MAY 23 2013
.SYNOPSIS...A SLOW MOVING COLD UPPER-LEVEL LOW WILL CONTINUE TO
PRODUCE SHOWERS WITH ISOLATED EVENING THUNDERSTORMS MAINLY OVER THE
MOUNTAINS. THE UPPER LOW WILL WOBBLE AROUND THE PACIFIC NORTHWEST
INTO THE MEMORIAL DAY WEEKEND AS IT SLOWLY FILLS AND WEAKENS. THE
COOL AIR MASS WILL GRADUALLY MODERATE INTO THE WEEKEND AND SHOWERS
WILL GRADUALLY DIMINISH STARTING TONIGHT.
&&
.SHORT TERM...THERE APPEAR TO BE TWO DISTINCT WEATHER REGIMES OVER
WESTERN WASHINGTON THIS AFTERNOON. ONE IS SCATTERED SHOWERS OVER
ABOUT THE NORTHERN THIRD OF THE AREA. THERE ARE SUN BREAKS AND HIGHS
HERE WILL BE 55-60. THE OTHER IS A LARGE AREA OF THICK CLOUDS AND
STEADY RAIN OVER THE SOUTHERN TWO THIRDS. THIS IS ASSOCIATED WITH
THE UPPER LEVEL LOW THAT IS CENTERED ALONG THE CENTRAL WASHINGTON
COAST. UNDER THIS SYSTEM CONDITIONS ARE QUITE GLOOMY WITH RAIN AND
TEMPERATURES IN THE 40S AND LOW 50S. BOTH KOLM AND KHQM ARE LIKELY
TO SET NEW LOW MAX RECORDS TODAY.
THE UPPER LOW IS FORECAST TO MOVE SOUTHEAST TONIGHT THEN FILL AND
MOVE NORTHEAST FRIDAY. AT LEAST THAT IS WHAT THE NAM AND GFS SHOW.
THE EURO KEEPS THE UPPER LOW OVER THE AREA THROUGH SUNDAY. ANYWAY
KEPT CHANCE POPS IN ALL PERIODS THROUGH SUNDAY...AND STILL HAVE A
SLOW WARMING TREND IN THE FORECAST. HIGHS SHOULD REACH THE LOW TO
MID 60S ON FRIDAY AND SATURDAY. BY SUNDAY IF THE UPPER LOW IS GONE
AND THERE IS ZONAL FLOW...A BIG IF...SKIES SHOULD BE PARTLY SUNNY
AND THERE COULD BE SOME LOW 70S AROUND. BURKE
.LONG TERM...THE GFS CONTINUES TO BRING A WEAK SYSTEM INLAND AROUND
MONDAY OR TUESDAY. THE EURO IS STARTING TO COME AROUND TO THIS IDEA
EXCEPT THAT IT SENDS THE SYSTEM SOUTH INTO OREGON AND CALIFORNIA.
HAVE RAIN LIKELY FOR A FEW PERIODS IN THE EXTENDED BUT AM NOT
CONFIDENT IN THE DETAILS. BACK TO SCATTERED SHOWERS STARTING ABOUT
WEDNESDAY. TEMPERATURES ARE LIKELY TO BE NEAR NORMAL. BURKE
&&
.AVIATION...A DEEP UPPER LOW CENTERED OVER WESTERN WASHINGTON THIS
AFTERNOON WILL REMAIN OVER THE REGION THROUGH FRIDAY...PROBABLY
SHIFTING SLOWLY EASTWARD. FLOW AT THE SURFACE AND ALOFT WILL BE
GENERALLY LIGHT AND VARIABLE. THE AIR MASS WILL BE MOIST AND WEAKLY
UNSTABLE.
FAIRLY SOLID SHOWERY PRECIPITATION COVERS THE SOUTHERN HALF OF THE
FORECAST AREA THIS AFTERNOON...WITH MORE SCATTERED SHOWERS TO THE
NORTH. IT WILL CONTINUE THROUGH TONIGHT ESPECIALLY OVER THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA...AND SHOWERS SHOULD DECREASE
SOMEWHAT FRIDAY. THERE IS ROUGHLY A 15 PERCENT CHANCE OF
THUNDERSTORMS THIS AFTERNOON AND EVENING.
THERE WAS AGAIN A WIDE MIX OF CONDITIONS ACROSS THE FORECAST AREA AT
2 PM. MOST OF THE AREA HAD LOW-END VFR CONDITIONS BUT THERE WERE
ALSO LOCAL CEILINGS OF BKN020-030...AND MUCH OF THE COAST AND SOUTH
INTERIOR IS IFR WHERE PRECIPITATION IS MORE SOLID. THIS KIND OF
VARIABILITY WILL BE THE RULE THROUGH TONIGHT AND FRIDAY MORNING. BY
FRIDAY AFTERNOON VFR CONDITIONS SHOULD BECOME MORE WIDESPREAD.
CONFIDENCE IN FORECAST DETAILS REMAINS RATHER LOW.
KSEA...MAINLY SOUTHWEST WIND 4-10 KT...EXCEPT PROBABLY LIGHT
NORTHEAST FOR SEVERAL HOURS LATE TONIGHT. ROUGHLY A 10 PERCENT
CHANCE OF A THUNDERSTORM THROUGH THIS EVENING. MCDONNAL
&&
.MARINE...A 1014 MB LOW OVER THE WASHINGTON OFFSHORE WATERS WILL
WEAKEN AND MOVE SOUTHEAST INTO NORTHWEST OREGON TONIGHT. WEAK
ONSHORE FLOW WILL DEVELOP FRIDAY AND CONTINUE SATURDAY AND SUNDAY.
SMALL CRAFT ADVISORY WESTERLIES ARE LIKELY IN THE CENTRAL STRAIT OF
JUAN DE FUCA AND EAST ENTRANCE FRIDAY NIGHT...AND POSSIBLY AGAIN
SATURDAY AND SUNDAY NIGHTS.
A FRONT WILL APPROACH THE PACIFIC NORTHWEST FROM THE WEST MONDAY AND
WEAKEN AS IT MOVES INLAND MONDAY NIGHT. AT THIS POINT IT LOOKS LIKE
IT WILL PRODUCE SMALL CRAFT ADVISORY WINDS OVER THE COASTAL WATERS.
WEAK ONSHORE FLOW WILL DEVELOP AGAIN TUESDAY. MCDONNAL
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...NONE.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
000
FXUS66 KOTX 232121
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
221 PM PDT Thu May 23 2013
.SYNOPSIS...
Cool and showery weather will continue through Saturday then a
subtle warming and drying trend is anticipated by Monday as the
persistent upper-level low moves out of the area. The break will
be short-lived as another cool and showery pattern returns around
the middle of next week.
&&
.DISCUSSION...
Tonight and Friday...A large closed low near the central
Washington coast this afternoon will move southeast towards
Portland overnight. As it does so most of the rain associated with
this low will remain south and west of the area. However...a cold
pool aloft associated with this large low will result in an
unstable atmosphere through early this evening promoting isolated
showers except for a bit more coverage near the Cascades given
closer proximity to low. LAPS data this afternoon also shows
surface based CAPE values of 200-400 J/KG near the Cascades, and
over the Blue Mountains where a few lightning strikes are
possible. Once daytime heating is lost, these showers will fall
apart with dry conditions expected for the late evening and
overnight hours. Another cool night is in store with localized
freezing temperatures possible in the Okanogan Highlands and
Northeast Washington valleys where skies are expected to clear
more significantly overnight. On Friday the low will move east
across south central Washington in the morning...and then rotate
northeast towards the Spokane and Palouse areas in the early
afternoon...and finally into the Central Panhandle Mountains mid
to late afternoon. This is the solution the ECMWF and NAM models
show and is preferred...compared to the slightly more southerly
GFS track. This will promote a cool and showery day over the
Inland Northwest with the greatest coverage of showers focused
along the low track and in the mountains. There will be a slight
chance of thunderstorms Friday afternoon as well over the area
with forecast CAPES of 200-500 J/KG over the region. JW
Friday night through Sunday night: The upper-level low that
has been parked over the region the last few days will continue
to have an influence on the weather but does show signs of
filling/warming. This will translate into less widespread and
weaker shower activity each afternoon; especially across the
Columbia Basin and into the latter half of the holiday weekend.
There are a few weak waves embedded within the parent low which
will keep a slight chance for PoPs during the overnight periods at
times...but in general, most shower activity will be middle to
late afternoon and focused over the northern and eastern
mountains. The best chance for thunderstorms will be Friday
evening...with very small chances Saturday...then a slight threat
near the Blues and Camas Prairie Sunday. Temperatures over the
period will be slowly climbing back near seasonal readings or
upper 60`s to mid 70`s. /sb
Monday through Thursday...Some significant shortwave features of
note to lock in on and add more detail courtesy of general
longwave trof lingering and influencing a good portion of the
Western United States through this time interval. Significant
features of note include what could be described as a deformation
zone of sorts sandwiched between the upper right corner of a large
low embedded in the longwave trof that gets squashed against
higher pressure influencing Central Canada that the GFS in
particular has lingering on and influencing Wednesday and Thursday
with continued wet weather. Otherwise Monday into very early
Tuesday morning appear to be the interval potentially least cluttered
with shortwave triggers so it remains assigned with the lowest
pops. Tuesday afternoon/evening are hinted at as having negatively
tilted trof passing as a kicker thus the pops and precipitation
amounts show an increase. Due to this longwave trof pattern
persisting forecast temperatures will generally remain on the cool
side of what would be considered normal for this time of year
through this time interval. /Pelatti
&&
.AVIATION...
18Z TAFS: A closed low west of the Cascades will promote showers
over the Inland Northwest today with an increase in activity this
afternoon as the atmosphere destabilizes. Showers will be mainly
focused near the Cascades (closer to the low center), and in the
mountains but with instability over all the area can not completely
rule out a shower for any locations. Instability however will be
greatest near the Cascades and near the Blue Mountains where an
isolated thunderstorm is possible between 21z today through 03z this
evening. Showers should quickly end between 3-5z with the loss of
daytime heating before the next wave brings an increase in clouds
12-18z with the chance for showers increasing again...mainly near
the Cascades and over southeast Washington. CIGS should stay
primarily VFR at the TAF sites. A brief period of BKN020-030
stratocumulus is possible for most TAF sites through 19-20z today.
JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 40 56 42 63 44 67 / 20 60 30 20 10 10
Coeur d`Alene 38 56 41 63 42 67 / 10 60 40 20 20 20
Pullman 37 55 40 63 41 66 / 20 60 30 20 20 20
Lewiston 43 61 45 70 48 73 / 20 50 30 20 20 30
Colville 36 62 42 67 43 73 / 20 50 50 40 30 20
Sandpoint 36 58 40 62 40 66 / 10 70 50 30 30 30
Kellogg 39 54 41 60 43 64 / 10 70 60 40 30 20
Moses Lake 42 64 46 72 47 75 / 20 40 20 10 10 0
Wenatchee 43 63 48 69 48 72 / 30 40 20 10 10 0
Omak 36 64 42 68 42 73 / 20 40 30 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KPQR 232118
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
230 PM PDT THU MAY 23 2013
.SYNOPSIS...AN UNSEASONABLY COLD UPPER LEVEL CLOSED LOW WILL REMAIN
OVER THE PAC NW INTO FRI...CONTINUING TO WRAP MOISTURE AROUND MUCH
OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON. THE LOW WILL BEGIN TO
MOVE EAST FRIDAY AND THE PRECIPITATION WILL BREAK UP INTO A MORE
SHOWERY PATTERN. TEMPS WILL WARM A BIT OVER THE WEEKEND...BUT A
CHANCE FOR SHOWERS WILL REMAIN AS WEAK ENERGY MOVES THROUGH. A
COUPLE OF SYSTEMS ARE EXPECTED NEXT WEEK FOR MORE PRECIPITATION
CHANCES.
&&
.SHORT TERM...THE UPPER LOW THAT HAS BEEN OVER THE PACIFIC NW THE
PAST COUPLE OF DAYS WAS STILL OVER WESTERN WA EARLY THU AFTERNOON. A
SHORT WAVE ROTATING AROUND THE LOW WAS PUSHING SW OFF THE N WA
COAST...WITH RADAR SHOWING A LARGE AREA OF RAIN AHEAD OF THE
SHORTWAVE EXTENDING FROM OFF THE WA COAST INTO NW OREGON. AS THIS
WAVE SWINGS AROUND THE LOW AND THROUGH OREGON OVERNIGHT...SHOULD SEE
RAIN INCREASE AGAIN OVER MOST OF THE AREA OVERNIGHT. MODELS WITH
THIS SYSTEM HAVE TENDED TO UNDERESTIMATE RAINFALL AMOUNTS...BUT SEEM
TO HAVE HAVE ADJUSTED SOMEWHAT WITH THE LATEST RUN.
ONCE THIS WAVE MOVES THROUGH...MODELS INDICATING THE THE MAIN PART
OF THE UPPER LOW LIFTS NE TOWARDS SOUTHERN ALBERTA FRI. TO VARYING
DEGREES MODELS SUGGEST A WEAKER SHORTWAVE STILL ON THE BACKSIDE OF
THE LOW FRI...SO WILL LEAVE LIKELY POPS IN THROUGH FRI. AFTER
THAT...A FEW MORE SHORTWAVES STILL EXPECTED SAT INTO SUN...THE MOST
PROMINENT OF WHICH PUSHES INLAND S OF THE FORECAST AREA SUN MORNING.
A MODEST ONSHORE FLOW PERSISTS THROUGH THE PERIOD...NECESSITATING
THE INCLUDION OF POPS THROUGH THE WEEKEND.
.LONG TERM...WESTERLY FLOW ALOFT LIKELY TO BE PERSIST THROUGH THE
EARLY PART OF THE WEEK. THIS WILL KEEP REGION UNDER A PERSISTENT
CHANCE FOR RAIN AS A SERIES OF SHORTWAVES MOVES THROUGH. THE
WESTERLY FLOW OFF THE PACIFIC WILL KEEP TEMPERATURES
MODERATED...LIKELY A LITTLE BELOW SEASONAL AVERAGES. MODELS TEND TO
DIVERGE SOME LATE IN THE WEEK WITH GFS AND CANADIAN CUTTING OFF AN
UPPER LOW OFFSHORE. BOTTOM LINE THOUGH IS FOR A CONTINUATION CHANCE
OF RAIN.
&&
.AVIATION...CIGS HAVE IMPROVED A BIT THIS AFTERNOON...WITH MVFR
MOSTLY ALONG THE COAST AND FAR N INTERIOR AND VFR ELSEWHERE. HOWEVER
AS UPPER LOW OF WASHINGTON COAST DRIFTS A BIT TO THE S AND SW
TONIGHT...SHOULD STILL SEE RA AND MVFR CONDITIONS SPREAD ACROSS THE
REGION THIS EVENING AND TONIGHT. STEADY PRECIP ENDS LATER TONIGHT
BUT MOIST AIR MASS STILL SUPPORTING QUITE A BIT OF MVFR CIGS. WILL
SEE CONDITIONS BECOME VFR OVER MOST AREAS ON FRI WITH SCATTERED
SHOWERS. CASCADES FREQUENTLY OBSCURED THROUGH TONIGHT.
KPDX AND APPROACHES...MIX OF VFR AND MVFR UNTIL 00Z OR 01Z...THEN
WILL HAVE INCREASING MVFR CIGS AS RAIN INCREASES. CIGS IMPROVE A BIT
LATER TONIGHT...BUT STILL HIGHER END MVFR. ROCKEY.
&&
.MARINE...SEAS WERE STILL BOUNCING BETWEEN 9 AND 10 FT...BUT WILL
CONTINUE TO SUBSIDE TONIGHT AND FRI. BROAD LOW PRES STALLED OFF
THE WA COAST AND WEAK PRES GRADIENTS...SO WINDS MOSTLY 15 KT OR
LESS. LOW PRES WILL MOVE INLAND AND WEAKEN FRI AND SAT.
THE NEXT SYSTEM COULD INCREASE WINDS/SEAS LATER SUN OR MON...BUT
STILL UNCERTAINTY ON THE TRACK AND STRENGTH OF THIS SYSTEM. NO
CHANGES FOR NOW...AS LOOKS TO BE DECENT POTENTIAL FOR 20 TO 25 KT
SOUTHERLY WINDS WITH THAT FRONT. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS UNTIL
6 PM TODAY...AND AGAIN BETWEEN 3 AM AND 8 AM FRI.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 231743
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1043 AM PDT Thu May 23 2013
.SYNOPSIS...
Cool, showery weather will continue over the Inland Northwest due
to a lingering upper low. Snow will also be possible over the
mountains. Conditions could moderate a bit by the weekend, as the
low moves out of the area, but it will be replaced by another cool
low sometime early next week.
&&
.DISCUSSION...
A closed low near Seattle this morning will remain west of the
Cascades today. Low level southeast upslope flow and abundant
boundary layer moisture will continue to produce scattered rain
showers along the East Slopes of the Cascades this morning with
isolated showers in the Wenatchee area. Elsewhere shower activity
will hold off until the afternoon hours when the atmosphere
destabilizes. With no organized disturbance to kick off these
showers...they should be mostly isolated in nature...except
scattered Wenatchee area and numerous along the East Slopes with
the low level upslope into these areas and closer proximity to low.
Latest model guidance still points at the East Slopes of the
Cascades, and areas near the Blue Mountains/Camas Prairie as
having the best instability for isolated thunderstorms so this was
maintained in the latest forecast. With persistent cloud cover
expected today for the Wenatchee area, Okanogan Valley, and East
Slopes of the Cascades high temperatures were lowered a bit. Also
lowered Spokane area a few degrees with stratus holding temps down
a bit this morning. JW
&&
.AVIATION...
18Z TAFS: A closed low west of the Cascades will promote showers
over the Inland Northwest today with an increase in activity this
afternoon as the atmosphere destabilizes. Showers will be mainly
focused near the Cascades (closer to the low center), and in the
mountains but with instability over all the area can not completely
rule out a shower for any locations. Instability however will be
greatest near the Cascades and near the Blue Mountains where an
isolated thunderstorm is possible between 21z today through 03z this
evening. Showers should quickly end between 3-5z with the loss of
daytime heating before the next wave brings an increase in clouds
12-18z with the chance for showers increasing again...mainly near
the Cascades and over southeast Washington. CIGS should stay
primarily VFR at the TAF sites. A brief period of BKN020-030
stratocumulus is possible for most TAF sites through 19-20z today.
JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 41 60 42 64 45 / 20 20 40 30 20 10
Coeur d`Alene 58 39 59 41 64 43 / 20 20 50 40 20 20
Pullman 60 38 56 40 64 42 / 20 20 50 20 20 20
Lewiston 66 45 63 45 71 49 / 20 10 50 20 20 20
Colville 63 38 67 42 69 43 / 30 30 50 50 40 30
Sandpoint 57 36 62 40 63 40 / 20 20 60 50 30 30
Kellogg 55 39 56 41 60 44 / 20 20 60 50 40 40
Moses Lake 64 43 68 46 72 47 / 20 20 30 20 10 10
Wenatchee 59 44 66 48 69 49 / 40 30 40 20 10 10
Omak 62 38 68 42 69 43 / 30 30 40 30 30 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KSEW 231612
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT THU MAY 23 2013
.SYNOPSIS...A SLOW MOVING COLD UPPER-LEVEL LOW WILL CONTINUE TO
PRODUCE SHOWERS WITH ISOLATED AFTERNOON AND EVENING THUNDERSTORMS
MAINLY OVER THE MOUNTAINS TODAY. THE UPPER LOW WILL WOBBLE AROUND
THE PACIFIC NORTHWEST INTO THE MEMORIAL DAY WEEKEND AS IT SLOWLY
FILLS AND WEAKENS. THE COOL AIR MASS WILL GRADUALLY MODERATE INTO
THE WEEKEND AND SHOWERS WILL GRADUALLY DIMINISH STARTING TONIGHT.
&&
.SHORT TERM...UPPER LEVEL LOW IS SPAWNING WIDESPREAD SHOWERS OVER
THE COAST AND SOUTHERN AREAS WITH SCATTERED SHOWERS ELSEWHERE. THERE
ARE NOTABLY MORE SUN BREAKS TODAY AND HIGH TEMPERATURES SHOULD BE
HIGHER THAN YESTERDAY...MOSTLY 55-60. AS THE LOW PIVOTS EAST THEN
SOUTH WESTERN WASHINGTON WILL BE UNDER AN AREA OF DIVERGENCE ALOFT.
MODELS SHOW NEGATIVE LIFTED INDICES THIS AFTERNOON AND EVENING
MAINLY OVER THE CASCADES BUT ALSO TO SOME EXTENT OVER THE INTERIOR
LOWLANDS. ISOLATED THUNDERSTORMS WITH SMALL HAIL ARE POSSIBLE.
BOTH THE NAM AND THE GFS LIFT THE UPPER LOW NORTHEAST AND FILL IT ON
FRIDAY. THIS WOULD KEEP SCATTERED SHOWERS IN THE FORECAST ESPECIALLY
OVER THE MOUNTAINS. THEN THESE MODELS DAMPEN THE UPPER LOW FURTHER
INTO A BROAD UPPER TROUGH ON SATURDAY AND JUST ZONAL FLOW SUNDAY.
THE EURO IS NOT IN COMPLETE AGREEMENT WITH THESE IDEAS AND KEEPS
SOME SEMBLANCE OF THE UPPER LOW OVER THE AREA THROUGH SUNDAY AND
BEYOND. HOWEVER THE LATEST RUN OF THE EURO HAS GONE SOME WAY TOWARD
THE OTHER MODELS. SO THE FORECAST OF SLOW WARMING AND LOWERING OF
POPS AS TIME PROGRESSES HAS SOME SUPPORT. HIGHS OVER THE INTERIOR
WILL BE IN THE LOW 60S FRIDAY AND THE MID 60S SATURDAY AND SUNDAY.
SOME SORT OF WEAK SYSTEM IS LIKELY MONDAY. BURKE
.LONG TERM...PREVIOUS DISCUSSION...ANOTHER UPPER LEVEL LOW WILL
BRING MORE RAIN TO WESTERN WA ON MEMORIAL DAY. BUT THERE ARE SOME
TIMING DIFFERENCES IN THE MODELS. THE GFS IS THE WETTER MODEL. THE
ECMWF IS SLOWER WITH PRECIP HOLDING OFF UNTIL THE AFTERNOON...AND
MAINLY AFFECTING AREAS SOUTH. SO EXACT DETAILS ARE STILL UNCLEAR AT
THE MOMENT. MODELS KEEP A LONGWAVE TROUGH OVER THE REGION THROUGH
MIDWEEK FOR ADDITIONAL SHOWERS WITH TEMPS NEAR OR SLIGHTLY BELOW
NORMAL. 33
&&
.AVIATION...A DEEP UPPER LOW CENTERED OVER WESTERN WASHINGTON THIS
MORNING WILL REMAIN OVER THE REGION THROUGH TONIGHT. FLOW AT THE
SURFACE AND ALOFT WILL BE GENERALLY LIGHT AND VARIABLE. THE AIR MASS
WILL BE MOIST AND WEAKLY UNSTABLE. SHOWERY PRECIPITATION IS MAINLY
ALONG THE COAST AND IN THE SOUTHWEST INTERIOR THIS MORNING. IT WILL
CONTINUE THROUGH TONIGHT ESPECIALLY OVER THE SOUTHERN TWO-THIRDS OF
THE FORECAST AREA. THERE IS ROUGHLY A 15 PERCENT CHANCE OF
THUNDERSTORMS THIS AFTERNOON AND EVENING.
THERE WAS A WIDE MIX OF CONDITIONS ACROSS THE FORECAST AREA AT 8 AM
-- IFR DUE TO FOG AT KBLI WHERE SKIES WERE CLEAR PART OF THE
NIGHT...LOW-END VFR AND MVFR OVER MOST OF THE PUGET SOUND REGION...
AND MAINLY LOWER CONDITIONS IN SHOWERS ALONG THE COAST AND IN THE
SOUTHWEST INTERIOR. THIS KIND OF VARIABILITY WILL BE THE RULE
THROUGH THE FORECAST PERIOD...MAKING CONFIDENCE IN FORECAST DETAILS
RATHER LOW.
KSEA...SOUTH TO SOUTHWEST WIND 4-8 KT. ROUGHLY A 10 PERCENT CHANCE
OF A THUNDERSTORM THIS AFTERNOON AND EVENING. MCDONNAL
&&
.MARINE...A 1014 MB SURFACE LOW WILL MOVE SLOWLY SOUTHWARD ACROSS
THE WASHINGTON OFFSHORE WATERS TODAY...THEN WEAKEN FURTHER AS IT
MOVES SOUTHEAST INTO OREGON TONIGHT. THIS FEATURE IS PRODUCING SOUTH
TO SOUTHWEST WINDS UP TO 20 KT OVER THE COASTAL WATERS THIS
MORNING...AND THE PLAN TO KEEP WINDS 20 KT OR LESS -- IE BELOW SMALL
CRAFT ADVISORY THRESHOLD -- LOOKS CORRECT.
ONSHORE FLOW WILL DEVELOP FRIDAY AND CONTINUE SATURDAY AND SUNDAY.
SMALL CRAFT ADVISORY WEST WINDS ARE POSSIBLE IN THE CENTRAL STRAIT
OF JUAN DE FUCA AND EAST ENTRANCE STRAIT EACH DAY DURING THE LATE
AFTERNOON AND NIGHTTIME HOURS. A FRONT WILL PROBABLY APPROACH THE
PACIFIC NORTHWEST FROM THE OFFSHORE WATERS MONDAY. MCDONNAL
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...NONE.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
000
FXUS66 KOTX 231548
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
848 AM PDT Thu May 23 2013
.SYNOPSIS...
Cool, showery weather will continue over the Inland Northwest due
to a lingering upper low. Snow will also be possible over the
mountains. Conditions could moderate a bit by the weekend, as the
low moves out of the area, but it will be replaced by another cool
low sometime early next week.
&&
.DISCUSSION...
A closed low near Seattle this morning will remain west of the
Cascades today. Low level southeast upslope flow and abundant
boundary layer moisture will continue to produce scattered rain
showers along the East Slopes of the Cascades this morning with
isolated showers in the Wenatchee area. Elsewhere shower activity
will hold off until the afternoon hours when the atmosphere
destabilizes. With no organized disturbance to kick off these
showers...they should be mostly isolated in nature...except
scattered Wenatchee area and numerous along the East Slopes with
the low level upslope into these areas and closer proximity to low.
Latest model guidance still points at the East Slopes of the
Cascades, and areas near the Blue Mountains/Camas Prairie as
having the best instability for isolated thunderstorms so this was
maintained in the latest forecast. With persistent cloud cover
expected today for the Wenatchee area, Okanogan Valley, and East
Slopes of the Cascades high temperatures were lowered a bit. Also
lowered Spokane area a few degrees with stratus holding temps down
a bit this morning. JW
&&
.AVIATION...
12Z TAFS: Low level moisture will promote areas of low clouds and
patchy fog this morning around north TAF sites...especially the
KGEG-KCOE corridor. At the same time an unstable upper low
remains in the region. This unusual set-up degrades confidence in
the persistence and timing of low clouds and fog. However expect
IFR conditions through 15-17Z, before mixing mixing and increased
instability with the nearby low helps lift the clouds. The
afternoon will bring an increased threat of rain showers and
perhaps some thunderstorms. The overall best threat will remain
closer to Cascades, near the center of the low, i.e. near KEAT.
The overall threat wanes after dark with the loss of daytime
heating, but a few showers will still remain possible near the
Cascades and Blue Mountains. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 41 60 42 64 45 / 20 20 40 30 20 10
Coeur d`Alene 58 39 59 41 64 43 / 20 20 50 40 20 20
Pullman 60 38 56 40 64 42 / 20 20 50 20 20 20
Lewiston 66 45 63 45 71 49 / 20 10 50 20 20 20
Colville 63 38 67 42 69 43 / 30 30 50 50 40 30
Sandpoint 57 36 62 40 63 40 / 20 20 60 50 30 30
Kellogg 55 39 56 41 60 44 / 20 20 60 50 40 40
Moses Lake 64 43 68 46 72 47 / 20 20 30 20 10 10
Wenatchee 59 44 66 48 69 49 / 40 30 40 20 10 10
Omak 62 38 68 42 69 43 / 30 30 40 30 30 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KPQR 231533
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
832 AM PDT THU MAY 23 2013
.SYNOPSIS...AN UNSEASONABLY COLD UPPER LEVEL CLOSED LOW WILL REMAIN
OVER THE PAC NW TODAY INTO FRI. THE LOW WILL CONTINUE TO WRAP
MOISTURE AROUND MUCH OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON
INTO FRIDAY. THE LOW WILL BEGIN TO MOVE EAST FRIDAY AND THE
PRECIPITATION WILL BREAK UP INTO A MORE SHOWERY PATTERN. TEMPS WILL
WARM A BIT OVER THE WEEKEND... BUT A CHANCE FOR SHOWERS WILL REMAIN
AS WEAK ENERGY MOVES THROUGH. A COUPLE OF SYSTEMS ARE EXPECTED NEXT
WEEK FOR MORE PRECIPITATION CHANCES.
&&
.SHORT TERM...UPPER LOW IS SEEN IN SATELLITE PICTURES OVER WESTERN
WA THIS MORNING. MAIN AREAS OF RAIN AS SEEN IN SATELLITE AND RADAR
IMAGES EXTENDS FROM THE N WILLAMETTE VALLEY NW TO OFF THE WA COAST.
MODELS SUGGEST SOME CONTINUATION OF RAIN IS LIKELY AROUND THE S PART
OF THE LOW...ACROSS THE NORTHERN PARTS OF THE FORECAST AREA TODAY...
BUT FOCUS SHIFTS TO THE SHORTWAVE ROTATING AROUND THE WESTERN
PERIPHERY OF THE LOW. THIS FEATURE SHOULD SPREAD MORE RAIN AROUND TO
THE NW PART OF THE FORECAST AREA THIS AFTERNOON.
REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...
THIS WILL BRING ANOTHER PERIOD OF ENHANCED PRECIPITATION TO MOST OF
THE FCST AREA THROUGH THE NIGHT. THE BACK EDGE OF THE WAVE SHOULD
PASS THROUGH TOWARDS DAYBREAK FRIDAY...WHICH SHOULD BRING AN END TO
THE HEAVIEST PRECIP.
SNOW LEVELS WILL HOVER AROUND 3500 FEET INTO FRIDAY...WITH THE SKI
RESORTS AND HIGHER TERRAIN OF THE CASCADES EXPECTED TO PICK UP
SIGNIFICANT ACCUMULATIONS. THE HIGHER MOUNTAIN PASSES WILL ALSO SEE
SOME SNOW. A COUPLE OF INCHES MAY STICK TO THE ROADS EARLY THIS
MORNING BEFORE ROAD TEMPS RISE ABOVE FREEZING TODAY...MELTING ANY
SNOW THAT ACCUMULATED OVERNIGHT. SNOW MAY STILL TRY TO STICK AT TIMES
LATER TODAY DURING ANY PERIODS OF HEAVIER SNOWFALL. THEN EXPECT SOME
ADDITIONAL LIGHT ACCUMULATIONS EARLY FRI MORNING AS TEMPS COOL AGAIN.
MOUNTAIN CLIMBING AND HIKING UP IN THE MOUNTAINS WILL BE HAZARDOUS
THROUGH FRI. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED TO HIGHLIGHT
THESE HAZARDS.
THE LOW BEGINS TO WEAKEN AND PUSH EAST OF THE REGION ON FRI. EXPECT
THE PRECIPITATION TO TURN MORE SHOWERY AND BROKEN UP. WE MIGHT SEE A
FEW BREAKS IN THE CLOUDS LATER FRIDAY WHICH COULD LEAD TO A MORE
DIURNAL SIGNAL TO THE SHOWERS FRIDAY AFTERNOON AND EVENING. TEMPS MAY
REACH 60 IN THE INTERIOR LOWLANDS.
MORE LIGHT SHOWERS ARE POSSIBLE ON SAT. MODEL UNCERTAINTIES INCREASE
OVER THE WEEKEND...BUT CONFIDENCE IS HIGH THAT THE PAC NW WILL REMAIN
UNDER THE INFLUENCE OF A TROUGHING PATTERN. HOWEVER...ANY SHOWERS
SHOULD REMAIN ON THE LIGHTER SIDE AND TEMPS WILL CONTINUE TO
MODERATE. MID 60S ARE A GOOD BET FOR MOST VALLEY LOCATIONS. SUNDAY
LOOKS QUITE SIMILAR TO SATURDAY...WITH LIGHT DIURNAL SHOWER CHANCES
EXPECTED TO CONTINUE. PYLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS.
THE MODELS SHOW MORE ORGANIZED SYSTEMS ARRIVING ALONG THE WEST COAST
EARLY NEXT WEEK WITH A CHANGE FROM INTERMITTENT SHOWERS TO STEADY
RAIN LIKELY DURING THE BEGINNING OF NEXT WEEK. SNOW LEVELS RISE
SLIGHTLY EARLY NEXT WEEK WITH TEMPERATURES STILL REMAINING SLIGHTLY
BELOW NORMAL. THERE IS STILL NO TENDENCY IN THE LONG RANGE FORECAST
FOR RIDGING TO RETURN TO THE NORTHWEST. KWELSON
&&
.AVIATION...WIDESPREAD MVFR CIGS WITH RAIN ACROSS REGION THIS AM.
BUT BETTER TO S OF KCVO WHERE HAS BEEN DRIER WITH VFR SKIES. NOT
MUCH CHANGE TODAY...AS ANOTHER ROUND OF LIGHT RAIN ARRIVES IN THE N
AND MAINTAINS STATUS QUO THROUGH AT LEAST 03Z. MIX OF VFR AND MVFR
TO S OF KCVO...BUT LIKELY TO SEE INCREASING MVFR CIGS IN THAT AREA
AFT 19Z. MVFR CIGS WILL PERSIST TONIGHT. CASCADES AND HIGHER TERRAIN
WILL BE PERSISTENTLY OBSCURED IN CLOUDS AND LIGHT PRECIP.
KPDX AND APPROACHES...NOT MUCH CHANGE TODAY INTO TONIGHT...WITH
MVFR CIGS AND LIGHT RAIN. MAY HAVE CIGS IMPROVE A BIT TONIGHT...
BUT STILL HIGHER END MVFR. ROCKEY.
&&
.MARINE...SEAS WERE STILL BOUNCING BETWEEN 9 AND 11 FT THIS AM.
EXTENDED SMALL CRAFT ADVISORY OUT UNTIL NOON. BY THEN SEAS WILL
FINALLY BY UNDER 10 FT. WITH BROAD LOW PRES STALLED OFF THE WA
COAST AND WEAK PRES GRADIENTS...WITH WINDS MOSTLY 15 KT OR LESS.
LOW PRES WILL MOVE INLAND AND WEAKEN FRI AND SAT.
THE NEXT SYSTEM COULD INCREASE WINDS/SEAS LATER SUN OR MON...BUT
STILL UNCERTAINTY ON THE TRACK AND STRENGTH OF THIS SYSTEM. NO
CHANGES FOR NOW...AS LOOKS TO BE DECENT POTENTIAL FOR 20 TO 25 KT
SOUTHERLY WINDS WITH THAT FRONT. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON TODAY
ON ALL COASTAL WATERS.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
| 
